Given the CDA had been investigating suspect activies in Monsters Inc. for over two years, it makes sense that Mike (somehow) convinced the agents to give him a shot and expose Waternoose through a Engineered Public Confession. If they hadn't been aware of what was going on, they would have arrested Mike and Sulley almost immediately.
Comforting thought: Randall had never actually used the Scream Extractor on a real kid, because if he had, he would have realized that you can’t actually suck screams out of someone.
Followed by Fridge Horror: if that trolley of scream containers is anything to go by, then what if he has?
Meaning Boo isn't the first child he kidnapped!
Or he could've tested it on Fungus or other monsters.
Meta: The slapstick scene where Phlegm fails at scaring the kid was presumably intended to calm down any kids in the audience who were freaked out by him trying to be scary, among other reasons.
The commentary confirms this. Originally, it was going to be Phlegm rising up, the kid screaming and then going to the next scene. The Phlegm fail was added to reassure kids it wasn't scary like with the opening sequence.
The energy metaphors. The Monster world had hit 'peak scream' due to the cynicism of our world, though screams were also a form of renewable energy. Waternoose's solution was strip-mining screams, leaving a trail of damaged or destroyed children and hastening the end. Sulley's discovery that children's laughter had far more power than their screams was something like the Monster World discovering fusion; near limitless energy that wasn't in the least diminished by our world's cynicism. That most of the Monsters' jobs got much more pleasant afterward was a very big bonus.
Boo's Offscreen Teleportation. It's almost like a supernatural killer in a horror movie — fitting, considering that human children are basically the monster world's equivalent of supernatural killers.
Boo can move from place to place in a manner that's almost invisible. It is fitting that Randall, who's capable of turning invisible, would be assigned to her.
"I'm watching you, Wazowski! Always watching!"... considering that Roz is the head of the CDA, she probably isn't all that crazy...
It also explains why she grim-facedly pulls down the shutter over her booth when the CDA first arrive. It's what she's supposed to do and she doesn't want anything to blow her cover, like an CDA agent obviously recognizing her.
This line also takes on a different light when you find out about Randall's scream extractor conspiracy. Roz probably suspects that Mike's not filing his paperwork properly because he's in on it, not just because he's distracted/lazy.
The fact he tried to ask about Randall's card key probably didn't help the matters.
In hindsight, there's another reason Roz suspects Mike. From her outside-perspective, he ran into the human world for unexplained reasons (in spite of being explicitly taught to avoid that), and got a promising scarer student to blow up a door by gathering an immense amount of energy, all before he could even graduate no less. Even if somebody managed to also blow up a door by overloading it with scream energy, that kind of track-record would make anyone a suspect on a watchlist... and then Mike (apparently) recruits that same scarer and joins one of the largest power companies of the Monster World and worms his way into the Scare Floor. Going by how she personally gets involved, it's likely that Mike was moved to the top of the watchlist.
Ever wonder why one of a pair of your socks disappeared when you were a kid? They probably got stuck to an unlucky monster like George Sanderson and nuked by the CDA...
Take a close look around the training room: everything seems a little "off." The pictures on the walls don't look quite right (animals have too many heads, etc.). The letters painted on the walls don't look right either; some of them are backwards or the wrong shape. This is because they're approximations made by creatures who don't quite know what these things really are. It's like a zoo or an aquarium: an imitation of a natural environment that is slightly off in ways that only a human could see.
Sulley has no idea that he was in the simulation room when Waternoose cornered him. He thought he actually went into Boo's room, and he had no idea Mike had set up everything to catch Waternoose's confession. But Sulley clearly pushed the button on the control panel, which would have activated the door, so why didn't it? Because Waternoose ordered the CDA to cut the power to the door stations. They must have cut the power to the station in the simulation room too! (But they left the power on to the cameras and TV's for some reason...)
Or maybe Sulley just pretended to push the button to trick Waternoose.
I'll provide Devil's Advocate somewhat here. They specifically cut the power to the Scare Floor, and only the Scare Floor. The station in the simulation room probably is not normally even plugged in, and the Simulation Room is a completely different circuit. It's like flipping the circuit breaker on a single fuse. That won't cut the power to the entire building.
How come Boo was capable of overcoming her fear for Randall at last, despite the latter being her worst nightmare and personal monster? She had been scared by Sulley not long beforehand, and having been exposed to the true terror of a number one-ranked scarer, anything else less than that turns much less frightening afterwards, Randall (the number two) included.
Children do take in from how their parents behave and Sulley and Mike were her parental figures? Having spent time with them allowed her to see that Randall isn't scary just a bully.
She also saw a lot of monsters, probably a few that looked somewhat like Randall. While she's specifically afraid of him, seeing similar monsters not being scary might have desensitized her.
The movie is premised on the idea that human kids are becoming less afraid of the monsters in their closets, causing an energy crisis in the monster world. We don't know why this change is happening in the human world, but the commercial Sulley and Mike watch seems to imply it's because of human kids watching television. This suggests a few possibilities:
These kids are consuming media that depicts Benevolent Monsters, like, for example, Sesame Street, thus dissuading their fear of the creatures. On the scare floor, one scarer returns from a child's bedroom in terror, describing how the little girl tried to hug him. Since he obviously went in to scare her, his approach didn't work at all in spite of trying to be fearsome.
On a related note, the older kids at least could also be watching like Jurassic Park or Godzilla in which monsters are cool. Perhaps the girl who tried to hug Claws was a Tomboy who thought he looked cool.
The kids are consuming media and TV that is more frightening than the monsters in their closet. This has some eerie real-world connections given that the film was released shortly after the September 11 attacks. They don't need monsters to give them nightmares when their own world has plenty to scare them already.
Funnily enough, if you listen carefully, the "dead" door the scarer exits is emitting rock music. This gives the implication the child wasn't "only six" anymore. The fact about children is, they don't stay six forever: they eventually turn into teenagers. It's possible that part of the reason children are growing harder to scare is because they are simply growing up, and Monsters Inc. is not keeping track of the subjects' age like they should.
Which is Roz is stern about scare assistants filing scare reports, as they likely include the children's birth dates.
But if that was the case, then this would be a normal thing, not something that is suddenly occurring.
For most of the movie, the monsters assume that human children are toxic. Fan theories hold that this notion may be a carry-over from the Spanish Flu pandemic, or even the Black Death. Assuming that monsters are not immune to the diseases humans suffer from, it's possible that the monsters of the past died of the diseases from the children they scared, resulting in the surviving monsters fearing that just touching the children might kill them too!
This makes sense when we consider that Monsters Inc. parallels the nuclear industry. The monster-world seems to get the vast majority of its energy from human children's screams, and because monsters believe humans to be toxic, they must be extra careful when around them; this is not too different from nuclear power being one of the most efficient methods of electricity production in the world, as well as nuclear workers dealing with radioactive materials and following strict protocols to prevent radiation poisoning and various disasters.
An alternative that falls into Fridge Horror instead is that, what if the myth was propagated intentionally with the point of stopping monsters from interacting with children. Remember all those folk tales about monsters kidnapping children in the middle of the night. Then what if the myth was spread specifically to put a stop to monsters with ill intentions kidnapping children. Puts the ending in a somewhat darker light now.
The Running Gag of Roz being obsessed with paperwork seems like an Obstructive Bureaucrat joke...until we learn that she's secretly the head of the CDA working undercover to unravel the conspiracy in the factory. In real-life companies, a company's records are often the most telling sign of evidence if something underhanded is going on—if someone's been cooking the books, there will be discrepancies in the files. That's why Roz is so determined to see every copy of every document: she's looking for leads on her case!
Randall, Waternoose and Fungus' facial expressions when observing the Scream Extractor test visualize their degree in villainy. Fungus is sad and remorseful, as he's a Punch-Clock Villain that's been roped into this, not to mention having experienced the effects of the machine himself. Waternoose is stern, as he takes no pleasure in doing it, but sees is as a necessary evil. Randall is gleeful, showing that not only was the machine his idea, he's also a sadist on top of it.
The Scream Extractor becomes a great deal scarier when you imagine that it's not Mike or Fungus, but rather a kidnapped child strapped to a chair with a metal pipe descending on their mouth literally ripping the air from their lungs, either suffocating them or giving them severe brain damage. Keeping in mind that the targeted children mostly would not have even been old enough to fully talk yet!
In the DVD Commentary, the writers mentioned that at one point, while Sulley is in Randall's lair going to rescue Boo, there was to be a shot where he stumbles into an entire room filled with empty cages, likely intended to house all of the kidnapped children after they were drained of their screams. Just the thought of such a thing casts a very haunting illustration of how widespread and horrifying this entire operation was going to be.
Not that a monster strapped to the scream extractor would fare any better, either. Fungus was lucky to not have suffered any permanent effects from the scream extractor, considering how pale he was in that scene, which would imply he was starved of oxygen.
Also, just think of what Boo's parents must have gone through when they went to wake up their little daughter the morning after she follows Sulley...
I always assumed that time moved differently in the human world and the monster world, such that by the time Boo got back, it was still the same night. All shots of Boo's room happen at night if memory serves.
It's possible she was gone no less than twelve hours her time if time is similar between the two worlds (it was nighttime in the monster world when Sulley first met her). Boo is not of school age, so she probably doesn't have a set time to wake up, though she will have to go to bed at around eight-ish if not earlier. Still doesn't make it less frightening for the parents.
I always assumed that her parents were worried, and went out looking for her, meaning they were searching their hometown whenever the monsters were in the room.
Consider what might have happened during the 15-minute sequence where Mike, Sulley, Boo, and Randall are riding around in the vault. There are millions of doors, so it's entirely possible that quite a few people would have opened one during that time, or even fallen to their deaths. Now imagine how much effort we would put into getting through one of those doors to find the victim–- and given the nature of what's through them, it's likely we'd come in all guns blazing.
That said, the majority of the closet doors are stacked behind other doors, so if they opened their closet, they would see another door directly in front of them.
Which, depending on your luck, may not be much better. Imagine accidentally walking into your closet to find another door in front of you, and you open it out of curiosity; depending on where you are at the exact moment Boo's laughing power wears off, you may wind up either trapped in the Monster World before you could go through another door, or in someone else's house in some completely random part of the Human World; either way, good luck getting back home!
And if you're met with the latter fate? Imagine you're suddenly in a child's bedroom in a completely random foreign country with your only way back home suddenly gone, the child in question sees you and calls for their parents, who come running in, see you and assume you're at best a trespasser or at worst broke in to harm their child! Even if you try to explain your situation, you either may be faced with parents not understanding you thanks to a language barrier, or they do understand you and outright assume you're lying. Either way they'd either kill you or have you arrested depending on what country you're in.
Or...] There is the possibility that the open doors from the other side could just be interpreted as All Just a Dream.
An in-universe example is the entire "Top Scarer" thing and the competition to earn that title earlier in the movie involving all the monsters going through many doors, and whoever scares the most children is Top Scarer. Naturally, Sulley keeps his title. At one point, he even comes out of a door and simply says "slumber party", which boosts his points just after Randall takes the lead. This suggests that he scared an entire room full of children and it's Played for Laughs. Flash forward to later in the movie when Sulley accidentally scares Boo with his roar and "scary face" that he's forced to demonstrate. Boo's reaction is recoiling and sobbing in absolute terror. Then Sulley undergoes a Heel Realization of just how bad scaring has messed up a kid. That brings about the Fridge Horror; just how many kids has he left as scared and sad as Boo is now? Knowing that, even the triumphant "slumber party" moment becomes much Harsher in Hindsight.
It's also noted in Monsters University that crying is useless to the monsters, and dangerous because it's likely to get them caught by parents. As such, monsters are trained to use specific scaring techniques that won't make children cry. This may also be another trick the company uses to get ethical monsters to accept an unethical power source— screams and tears are equally likely to bring parents running, but tears are more likely to cause the monster to sympathize with the target.
One also has to wonder how Sulley would consider his life directions if Waternoose had just gone with his word, put Boo in the right door and went "Okay, problem's over. Everyone back to scaring."
Well in Monsters at Work: Though he doesn't deny that it'd be easier if they were using Screams again, and that it's more secure than the experimental steps the company is taking with Laugh power, Sulley mournfully recounts to Tylor the time he accidentally scared Boo, noting that what hurt him most was what he saw of himself in her eyes when she was scared of him, realizing what he'd been doing to so many children. The point is made clear—even if the whole world went back to Scream Power, Sulley wouldn't go back to being a Scarer. His focus on spreading Laugh Power as a new energy source is not only his way to keep his friends and colleagues in a job, but to make sure that no more kids get emotionally hurt by the monsters who're simply doing their jobs. The moment is capped off by a brief rendition of Boo's Leitmotif as Sulley remembers what he did, and underlines his declaration that Laugh Power is not only better than Scream Power, but that it's the right thing to do, no matter how difficult the job gets
Early on, during a conversation between Celia and Mike, she mentions she might get her hair cut. The thing is, her individual snake-hairs have eyes and brains of their own.
Made worse when you see them cringe in horror and shock at her announcement on screen, then quite literally slump and sigh in relief when Mike told her he liked it the way it is.
I always assumed they would've grown back; it would've been painful, but by no means lethal.
Who says she doesn't have hair? We've never seen her without a shirt, for example...
As Sulley and Mike demonstrated, it seems to be quite easy to get back to the monster world simply by waiting by a kid's closet door until it's activated from the other side. So, assuming he wasn't Killed Off for Real by Crazy Shovel Lady, what's to stop Randall coming back and looking for revenge on Mike, Sulley and even Boo? Take a psychotic enemy who now has nothing to live for (since scaring as a profession has gone down the toilet and he'd be a wanted criminal anyway), who can climb walls, move silently and like lightning as well as turn invisible, and our favourite trio's futures start to look rather bleak...
The comic book has him set up Mike to be caught stealing laughter supplies, in order to create friction between Sulley and Mike, only to be caught by security footage he was likely planning to destroy.
Even assuming Sulley and Mike just got ridiculously lucky and he can't make it back to the monster world, the movie implies they at least have a vague idea where the kids they're scaring live. He's got plenty of time on his hands (decades, most likely), and nothing else to do, he could conceivably hunt down Boo in her own world.
Kingdom Hearts III has Randall being freed by Vanitas to take revenge but in the end, Randall is banished again. "Monsters Inc: Ride and Go Seek!" at Tokyo Disneyland also has Randall escaping the human world and tries to capture Boo again but is thwarted and compacted into a cube.
Blink and you'll miss it, but at the beginning of the movie, Sulley reads a file on a kid before going in the door. And in their commercial they mention that each child is matched to a monster that fits them. Now look at the number of doors and all the places the monsters are shown to go. So, basically, they have information about every child on the planet. And they use that information to scare them. Yeah....
Good thing it's onlyto scare them, rather than any physical harm or worse!
When Mike goes to find Sulley after their fight, he has to venture into an arctic climate with the blizzard possibly still going. Given his smallness and lack of hair, he could have frozen to death if he'd gotten lost.
Think about all the monsters that got banished. They don't know that children aren't toxic. They will think that they're living in our equivalent of a radioactive wasteland which there is no escape from. Those monsters probably had families and a secure place in their home... all gone. Now they live in an entirely different dimension, nowhere to go, and must put effort into not being found by humans, possibly killed, neither touching their poisonous territory. And they have no chance of ever getting home. Suddenly banishment doesn't sound so lighthearted anymore...
On that note, while the Abominable Snowman doesn't seem scared of kids, he also lives in a relatively remote region with little reason to interact with them, much less potentially be "killed" by them. Nessie may find herself feeling safer for the same reason— not many children would be willing to enter an abyssal, freezing cold lake. Poor Bigfoot, who lives closer to human society, probably suffered the most by comparison. This may be why he implicitly went crazy.
Picture this: a Scarer from Monster’s Inc is creeping in a child’s bedroom, getting ready to scare him/her. Then before the Scarer can scare the kid, one of their parents comes in and begins beating up the child and yelling abuse. What could the Scarer do? Try to save the child? Doubtful when monsters think all humans are toxic. Scare the parent into backing off? You’d need to be Sulley himself to pull that off. Let it happen and try to learn to live with the guilt? How the hell could the Scarer just stand/sit there and watch a mother/father assault and hurt the very child they’re supposed to protect? It wouldn't surprise me if any of the Scarers lack sympathy for humans because they've seen how cruel said humans can be.
However, most people would be pretty terrified of a large creature with sharp claws and/or teeth.
We don't get to see what exactly Randall got up to in the brief amount of time that he was in Boo's room with her still in there. However there's a lot to take in from how intense Boo's phobia of him was, considering she not only thought he was hiding in the closet when she went to sleep, but would also run and hide in terror just from seeing him or even sensing he's in the room. But the most disturbing part is the distinct sound that she makes throughout the movie to identify Randall, which somewhat sounds like her going "Owww!"
While, yes, that is bad, it's not as terrifying as it might seem. It doesn't take much for a toddler to become scared to the point of running away at the sight of something; some toddlers are even known to become afraid of their toys if they had a nightmare while sleeping with them. As for the noise she makes, even that might not be as scary as it seems, since toddlers often make bizarre mistakes about sensations and emotions, including mistaking negative emotions such as fear for pain.
In this teaser trailer, Sulley and Mike are locked out of a child's bedroom and have to break in using Mike's keycard. Why is there a lock on a child's closet door? It's not even a padlock, which one could imagine parents putting on the door if their child was scared of monsters in the closet. It's built into the door itself. If it really is to keep monsters out, the fact that the parents were willing to go to the expense of replacing the door suggests that they took the child's fears very seriously. One can only imagine how badly the child was scared to make his/her plea for protection that earnest.
With how wide and easily-accessible the chute to the trash compactor is, has anyone fallen in and subsequently been maimed or killed?
Given Cutter's many comments about past MIFTters, it's very likely possible. David was stated to have been killed in a shredder shaft.
Why do monsters scare humans to begin with? According the "History of the Monster World" short film included in the Monsters, Inc. DVD bonus, there was a primitive tribe called the Mons who tried to make friends with another tribe called the Mans, but the Mans thought the Mons were small, hairy, had bad breath, and smelled bad, so they frightened them away and drove them out to sea. The Mons swam to a tropical island where they became the first monsters after eating its strange food. After realizing how frightening they were, the monsters snuck back the Mans' homes at night and scared them. They found their revenge so sweet, they decided to make it their mission in life. For monsters, scaring humans isn't just a way to gain energy, but also a way to get revenge on humans for driving them away just because they were different.
, Sulley and Mike are locked out of a child's bedroom and have to break in using Mike's keycard. Why is there a lock on a child's closet door? It's not even a padlock, which one could imagine parents putting on the door if their child was scared of monsters in the closet. It's built into the door itself. If it really is to keep monsters out, the fact that the parents were willing to go to the expense of replacing the door suggests that they took the child's fears very seriously. One can only imagine how badly the child was scared to make his/her plea for protection that earnest.