The reasoning behind an Overclocking Attack — when a control console is destroyed, anything that it controls is automatically switched off.
This of course makes little sense when you think about it. Try switching your radio on, then pulling off the tuning knob. All you end up with is your radio stuck on whatever station you tuned it into. Every system should remain stuck like this after the control console is destroyed, but it never is.
This even happens with systems where it would make little sense to turn it off upon destruction. Why would you include a fail-safe that automatically- for example- lowers the shields of your starship when the console that controls the thing defending your starship is destroyed? And why wouldn't aforementioned vital system not have a secondary control console somewhere, or at least a Shield Dimmer Switch?
Ironically, the only systems that don't do this are usually also the ones that will cause a disaster if they can't be shut down, such as the main reactor.
It never sets off an alarm, either. Destroying an Insecurity Camera doesn't trigger some kind of automatic defence system, facility-wide alert or even notify the janitor. It just turns off the camera. Apperently nobody is watching the monitors for these cameras either, since they don't seem to notice when one suddenly goes offline.
This is most often a major flaw of the Big Bad's Doomsday Device and/or Supervillain Lair. But even the good guys fall victim to this with their extremely poor McGuffin-guarding security systems. Most often goes hand-in-hand with Computer Equals Monitor and Made of Explodium.
Not to be confused with Inventional Wisdom, where a literal switch brings about destruction of idiotic proportions. See No Ontological Inertia for a similar (and more illogical) trope.
Needless to say, while this trope can occasionally work in Real Life as in the few examples below, sometimes it is more dangerous to outright try to destroy something to "turn it off," especially if the something in question involves explosives/petrochemicals, other dangerous chemicals, radioactivity, or something similar. Trying to destroy an enclosed radioactive source, for example, may only increase the danger by opening the source and leading to an uncontrolled and immediately fatal release of radiation, and trying to destroy a suspected bomb will often make it explode. Meth labs are another example - even moving any of the components of a meth lab or being in its presence can lead to fatal or chronically injurious poisoning and/or an explosion, as many police officers not trained in safe chemical cleanup have unfortunately found out.
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Anime and Manga
Subverted on Yu-Gi-Oh! GX: Kenzan catches Saiou's Brainwashed minion after he has used a laptop to fire a missile from a Kill Sat, so he figures the best way to fix things is to destroy the laptop. It's not until after he's done so that someone tells him he's in fact destroyed the Off Switch. Did we mention Saiou is Dangerously Genre Savvy?
Something similar happened at the end of the Virtual Nightmare arc of Yu-Gi-Oh! — by destroying the console, Marik unintentionally destroyed the off switch.
Used at the end of the A Certain Scientific Railgun anime, where Ruiko Saten smashes the consoles controlling the Big Bad's psychic-power-limiting device, thus allowing her friends to use their powers and defeat the villain.
Averted in Star Wars. When Luke and Leia are being pursued by Stormtroopers on the Death Star, Luke shuts a blast door and destroys the console specifically to make it harder for them to open the door again. Unfortunately the controls for the bridge they needed were on the same panel...
The same movie plays it straight a few times as well. For instance, in the same exact scene. Why are the controls to the door only on one side of the door?
Played straight in The Phantom Menace where the destruction of the droid control ship causes the entire army of battle droids to shut off, and even fall apart.
The Droid Control Ship is given justification in the expanded universe: the droids stopped working because the Trade Federation was too cheap to outfit all the droids with processors, as well as being paranoid about them be used against them. The droids fell a part because they are held together magnetically. The stupidity of this was noted, and most of the droids used in the Clone Wars had central processors.
Averted in The Incredibles; in fact, it's the Omnidroid itself seeking to destroy its remote control, so it cannot be controlled by anyone else, and it's up to the Incredibles to try keep it safe until they can figure out how to operate it.
Averted in WarGames: when Joshua is trying to determine the codes to launch America's nuclear missiles by itself, General Beringer asks why they don't just unplug the computer. McKittrick explains to him, and the audience, that the system would interpret a shutdown as the destruction of NORAD, and would carry out the last instructions, i.e., launch.
Live Action Television
Happens many times on the various Star Trek series with force fields. Numerous episodes have characters shoot a control panel and a force field shuts off. Why even bother having access codes to unlock??
As seen in Cutting the Knot, Stargate characters frequently disable things, or otherwise get literally alien devices to do exactly what they want, by shooting random control crystals.
Averted in the Doctor Who story, The Seeds of Death, an Ice Warrior pulls a bunch of levers on a (very simple) control panel, and then shoots it, so it'd melt and nobody could change the setting. However as the system is otherwise undamaged, the Doctor is able to rewire a new setting.
Used as a last resort at the end of the Novacom arc of Adventures in Odyssey: Novacom blocked all methods to stop the uplink of their Mind Control radio waves. Although Whit and Tom find the machine, they can't turn it off; fortunately, the uplink is connected to a machine Novacom stole from Whit, and he stops it by making it self destruct. In this case, they were at least racing against a countdown and knew they had to destroy the machine before it sent its signal — destruction could prevent the operation from executing, but not turn it off if it started.
Security cameras suffered badly from this trope in both System Shock games. Blowing them up reduced the security of a level, rather than set off the alarm. The idea being that the security cameras are what SHODAN was using to track the player: the fewer of them there were, the more ignorant SHODAN was of the player's exact whereabouts.
It was to be explained in the game (but wasn't, for some reason), that the infestation has deployed some sort of gas, that corrupts metals. That was the explanation behind guns, that break from shooting ten times in a row, probably it could be the explanation for mad AI, that expects cameras to break on their own.
Same in Spiritual SuccessorBioShock, but come on: the system were made in the Fifties. Electronics in Rapture appear to run off of an electrified gel that runs through tiny pipes instead of actual electricity going through wires. Basically, they're what Descartes thought our nervous system was.
Same here as in system shock - the explanation for tubes was to be "There is a living human inside, that you increace the flow of ADAM to.", and the hacking minigame was made to reflect that. And then they went with other approach.
In Ghost Trick, a power failure caused when the electric chair that was being set up to execute Detective Jowd malfunctioned and exploded opened the doors of all the cells in the prison, setting the prisoners free. This is Handwaved a few moments later, as you're told it's a security measure. In all fairness, none of the prisoners were dangerous in any way.
In Tales of Xillia, the team at one point needs to shut off two generators to open a barrier. When they get to the first one, they wonder how to turn it off when Alvin volunteers, making it seem he knows something about them. Only for him to shoot the control panel, after which he smirks and Jude has a horrified look on his face. When the team visits the second generator, Milla smiles with approval, making Jude even more annoyed.
Averted in Teen Titans, in which Raven and Terra are arguing whether to destroy a control panel in order to shut off a device that's going to destroy the tower if they don't stop it. It ends up getting destroyed by random battle damage... which makes the device go faster.
Terra: Okay, maybe smashing the computer was a bad idea...
Averted in The Batman - Batgirl sabotages the doomsday device, the countdown stops...
Villain: What happened? Did we lose power?
Henchman: No, the countdown timer's disabled. The device is still operational.
Jonny Quest: The Real Adventures has a particularly egregious case in the final episode. When the crew use Questworld to track down a reality warping demon, it takes over the system, leaving Johnny trapped. His father saves him by taking an axe to the laptop. Never mind that based on everything established about Questworld so far, a stunt like that could potentially kill anyone connected.
Danny Phantom believed in this trope during the Christmas Special. In that episode, the Ghost Writer had used his keyboard to put a spell on Danny to teach him An Aesop and Danny destroyed the keyboard hoping it'd break the spell. In return the Ghost Writer told him the only two ways to end the spell would be somebody writing "the end" on the keyboard, which was no longer an option (Nice Job Breaking It, Hero, indeed), or Danny learning the aesop.
Recommendation to avert: The Evil Overlord List recommends that a Supervillain Lair's doors should lock if the controls on the outside are destroyed, and open if the controls on the inside are destroyed.
And to treat every security camera malfunction as enemy action, regardless of how flaky the system is.
A very common example - maybe a full subtrope? - is automatic doors controlled by some sort of scanner or keypad box on the wall. Shooting the control box will always make the door open. Unless it's a door you want closed in the face of an advancing enemy, in which case shooting it makes it lock shut. Seen It a Million Times.
Brake systems can work either way. In most passenger cars, any serious problem will cause the brakes to "fail open" and be unable to stop the car, because the system depends on hydraulic fluid reaching the pads to close them. But in locomotives and large trucks, the air brakes are designed so the system actively works to keep the pads open, which means any problem causes them to "fail closed" and bring the vehicle to an immediate stop.
These systems exist today. It's in the best interest of certain devices to "fail-open" or "fail-closed" in order to prevent damage to other connected devices. If power is lost to electronically controlled water valves, the valves may either "fail-open" or "fail-closed" (depending on the system) to protect the systems that they service. Likewise, electronically controlled steam valves have to "fail-open" so that steam pressure doesn't build up and rupture the pipes.
And simple secondary fail-safes are placed, usually being as simple as possible, in case of any kind of primary failure. For the steam pipe example, a burst disk that can only withstand a certain amount of pressure, a spring-mounted pressure valve where the steam pressure escapes when greater than the spring tension, or a thermal relief valve that uses a metallic rod that lengthens when heated to raise the valve cap.
Many functionally hot-pluggable buses aren't supposed to be, and in older computers yanking a keyboard cable (for example) could damage the motherboard. ROM cartridges are particularly risky, as apart from the ZIF socket on the original NES, most could easily damage the system from a voltage spike if a cart was removed. (It is not unheard of, however, for the truly inept to even try to hot-plug ISA or PCI cards, or even RAM modules. Disaster is occasionally averted, but even when the poor shlub gets lucky a reboot is usually required.)
A classic power switch works by bridging the connection when it's on. Most methods of destruction would leave a gap in the connection where the power switch used to be, thus disabling the device. Which is usually a lightbulb. A lot of work just to turn out the lights, isn't it?
Radioactive sources and/or anything that contains/uses a radioactive source are a strict aversion of this trope. The cladding and shielding of a radioactive source is what provides the most protection from both its radioactivity and its reacting with other material. Taking apart/destroying anything from a radiation therapy device to a nuclear reactor carelessly "to turn it off" or "to stop it" makes it more dangerous.
The Chernobyl, Three Mile Island, and Fukushima disasters are all fine examples of this - at Chernobyl, the containment was blown open by a steam explosion, leading to a massive release of radiation. At Fukushima, the earthquake itself damaged portions of the containment and the reactors, and it and the tsunami led to destruction of the cooling systems - which then led to corium overheating and melting through its containments. In Three Mile Island, that the containment was not completely destroyed in the accident was what prevented it from becoming a disaster on the level of Chernobyl or Fukushima. Another example, involving a radiation therapy device, is the Goiana incident, where salvage workers opened a containment on a radiation therapy device, leading to far more and far worse exposures than had the device been left alone.
As mentioned in the article introduction, drug labs (especially the notorious methamphetamine labs, but to a lesser degree MDMA and research chemical production) are something best left to professional chemical cleanup workers experienced in doing such. The reasons for this are many, but among others, exposure to the fumes or chemicals can do anything from poison someone to explode to cause cancer later on, that said labs are often set up in less than safe ways where moving something or creating even a static spark can cause an explosion, and that destroying something that is safely contained can lead to an explosion or poisoning. If you see one (or the leftover remains of one), the best move you can usually make is out of the area, as fast as possible.