Considering this article, nothing beats the Dutch children's program Theo En Thea (1985-1989). This controversial kids' show talked about topics that some parents (mostly overprotective ones) wouldn't see as fit to discuss with young children, such as prostitution, drug abuse, and sexual harassment. Despite all objections the show was both a hit with kids and adults alike!
Another gem of Dutch childrens' television: Purno De Purno. With characters such as the "Kittelaar" (a Dutch word for clitoris), politically incorrect gags about sex, homosexuality and bodily functions, political commentary and very suggestive imagery. Let's just say that in the '80s and '90s the Dutch didn't have such prudish hangups about shielding children from anything related to sex.
Nature documentaries in general might be classed as this. In the UK, at least, they're exempt from classification due to their educational nature when released as video recordings, so kids can theoretically buy them and watch them without question- even if they do contain animals fighting, killing and eating other animals and copulating. There may of course be some measure of What Measure Is a Non-Human? about this too- it's just what animals do naturally in the wild, so who cares?
ABC Family. Either ABC/Disney or Fox before them wanted to change it, but their contract with Pat Robertson requires them to keep "Family" in the channel name (and to run The 700 Club before midnight... maybe they could give it a Laugh Track?).
ABC Family also airs reruns of That '70s Show which has many references to sex and implies marijuana usage with the kids in the circle. Granted, it has both written and spoken warnings along the lines of "The following material may be inappropriate for younger viewers" before each episode.
Canadian networks such as YTV and Teletoon also seem to carry the same misconceptions as suggestive cartoons, a couple of violent anime, and shows targeted for older teens often run rampant or get scattered into the mix of stuff that's supposed to be for kids.
YTV did this with Farscape of all shows. They announced that they would be the first Canadian channel to carry the show... and put up a Farscape page in their website which looked like something from Nickelodeon. Apparently, they were misled by the fact that the show was made by The Jim Henson Company. They ended up only airing the first season (and censoring the crap out of it).
YTV also was the first to air Red Dwarf and ended up banning one episode entirely because there was too much to cut. However, YTV eventually got the hint and began airing more adult fare like Aeon Flux and The Young Ones in late-night time slots.
Ultraman Ace features plenty of kid-unfriendly kaiju violence.
Ultraman Nexus was given a Saturday morning time slot despite happily wallowing in depressing things and then killing off Ultraman's human host midway through the series.
Tsuburaya created a horror series in 1968 called Operation: Mystery. In Germany in 1971, some network decided it would be a good idea to dub it and broadcast it as a children's series. It's from the creators of Ultraman, after all... it must be for kids!
In the early 1970s Gerry and Sylvia Anderson decided to go into more serious, live-action drama with the series UFO, though it still used plenty of their famous model work. Unfortunately the networks didn't know what to do with a show about faceless aliens coming to Earth to steal people's organs, which included one episode about drugged out hippies and another which focuses on the lead character having an extramarital affair. After all, it was made by the creators of Thunderbirds so it must be for kids, right?
In one of the stupidest examples imaginable, numerous parents apparently assumed that Game of Thrones had to be family-friendly because it was fantasy. It didn't help that a number of articles written about the show hyped the fantasy aspects, such as mentions of dragons and direwolves, or focusing entirely on the latter part of series co-creator David Benioff's admittedly crappy tagline "The Sopranos" in Middle-earth", apparently hearing "Middle-earth" and assuming we'd see elves, wizards and hobbits. Never mind that it airs on HBO, which is known for series with copious amounts of nudity, violence and profanity, and never mind that right before the series a giant "Not suitable for children" warning is displayed. There were angry emails to HBO and news outlets from outraged parents at a show "for children" containing beheadings, profanity, incest, nudity and rape.
Glee, largely thanks to the popularity of a movie with a very similar premise that actually was for kids. Except Glee has: jokes about oral sex; dancing which borders on dry humping; sex between teenagers and older, married adults; the president of the celibacy club getting pregnant; boys complaining about "erupting early" and an adult former student corrupting kids by giving them pornography, alcohol and lessons in stealing. And that's all within the first 5 episodes.
The media appearances of certain Glee actors have been criticized by some "concerned parents" groups for being too sexy for young children watching the show.
Glee in its early days got this in droves. Many people thought it was High School Musical: The Series, without realizing that characters freely swear and the show tackles several heavy issues like drug use, infidelity, teen pregnancy, losing one's virginity, homophobia, etc. It doesn't help that Glee covers are often played on Radio Disney, or that much of its marketing is made to appeal to the tween crowd.
Many people assume that because Kermit, Fozzie, and the rest of The Muppets have been family friendly for the past couple of decades, that the original Muppet Show is also a children's show.
This applied even back when the show originally aired. Jim Henson had a very hard time selling the show to U.S. studio heads who couldn't see puppets as anything but for kids. This article shows some clips from the early days of Sesame Street that would not be suitable for children today.
The Boy With The Cuckoo Clock Heart. The main character names his pet hamster Cunnilingus, a word he learned from a hooker. He thinks it's the name of a Greek hero. There is a lot of erotica in the book.
Buffy the Vampire Slayer doesn't shy away from showing vampires and demons being stabbed or decapitated, human victims lying gruesomely dead, and has a significant amount of sexual content. Nevertheless, there are 7-year-olds whose parents have allowed them to watch it.
The original 1992 movie, despite also not being for kids, was marketed to appeal to young teens and tweens, primarily because Paul Reubens (you know, Pee-wee Herman!) was going to be in it. (This becomes really interesting when you remember that Reubens had been arrested for indecent exposure less than a year before, and that his vampire character in Buffy is made up to look almost exactly like his mugshot photo.) Though, the film does have mostly Bloodless Carnage (the most blood we see is when Buffy has a cut on her elbow!) and is unlikely to frighten any but the smallest children.
Mystery Science Theater 3000: Children are especially attracted by the funny puppets - and really the host segments have a wild, kids-showish atmosphere and a fairly family-friendly sense of humor. The actual films being covered, though, are often not kid stuff and often deal with mature themes. The obviously fake monsters to an adult are not so obviously fake to small children, no matter how much the 'bots may be laughing at them. Most children simply do not have enough cultural experience to understand when a movie is a "bad" movie.
It should be noted however, that they got several letters from kids and families (paticularly during the Joel years) talking about how much they loved the show. These letters were often read on the air, showing that they embraced younger audiences watching.
The short-lived television series Probe accidentally sparked a bit of outrage with this trope. In one episode, misanthropic genius Austin tells his secretary that he knew Santa Claus was a myth at the age of seven (he had set up a motion-controlled camera pointed at the chimney). Since the show was appearing during a family-friendly hour, there were young viewers ambushed by this revelation, resulting in complaints from Moral Guardians.
The Goodies, being essentially a live action version of a Looney Tunes cartoon, was broadcast in a children's timeslot by the Australian Broadcasting Company ... who had to edit the hell out of it.
The makers of Torchwood must have thought that by series 4 there was no longer any need to keep saying "Yes, we know this is a Doctor Who spin off, but it's broadcast at 9pm for a reason", so they didn't. Cue outrage at the first gay sex scene, with more than one person tweeting to the effect of "That's not right, it's a kids' show". Clearly the post-watershed swearing and gore and a paedophile as a major character didn't clue them in enough.
Crank Yankers has some well-known comedians make prank calls to various businesses, and reenacting the call on camera using muppet style puppets. One call had a woman prank a hardware store with an extended conversation about the "big tubes of caulk." Very much not for children.
Not to mention the openings of the skits. One has a man carrying his large testes in a wheel barrel and another has a woman puppet's clothes being ripped off in the wind and exposing her breasts and nipples, fully.
It's a given that regular Super Sentai can have stuff that some may consider pushes the envelope especially those outside Japan. As far as violence goes this is no more violent then the regular series. Aside from episode 3 which was definitely not for kids the series didn't push it that much further than Super Sentai with the occasional cleavage shot or even face in cleavage shot, some brief nudity, and other sexual overtone being the biggest thing that made this a series not for kids.
Degrassi gets this too, despite the fact that it's usually rated TV-14 and has characters dealing with a plethora of (mostly non child-friendly) challenges, such as eating disorders, peer pressure, sexual identity, gang violence, self-injury, teenage pregnancy, drug abuse, school shootings, rape, etc.
Miniseries/film Fractured Fairy TaleThe 10th Kingdom. It's fine for older kids, mostly thanks to Parental Bonus, but many a parent decided, like all Fairy Tales, it was intended for kids. There are references to aforementioned glowing hot slippers, onscreen deaths and a main character standing trial for eating a girl, who was actually killed by her uncle. Also, Rutger Hauer with a crossbow.
Let us not forget how the opening of the first episode showed us a shot of the Snow White Memorial Prison, with a bunch of buzzards eating the remains of prisoners in old hanging cages... yes, very family friendly fairy-tale indeed...
Blue Bloods used this trope In-Universe at one point. Henry and Frank were going to take Danny's kids (roughly eight years old) to a Broadway musical, but Henry misplaced the tickets. When they found them, Erin noted they'd "dodged a bullet" as she put it: the musical was The Book of Mormon.
Strange enough reality TV shows are seldom seen as harmful for children. Despite the fact that many of them feature a bunch of people stuck together in one place while the TV makers make sure the tensions between them rise. The result is often a showcase of verbal and/or physical fights, swearing and people trying to get revenge on each other. Now, isn't that a great example for your kids growing up?
Related to this is the fact that certain female socialites and/or reality stars who get their fame from these reality shows (i.e. Paris Hilton, Nicole Richie, the Kardashian sistersnote Kim, Khloe, and Kourtney — with Kim the most popular out of the three, Nicole "Snooki" Polizzi from Jersey Shore), are frequently criticized by other media for being "bad role models" for girls. Never mind that the shows they've appeared on were never aimed at children young enough to be harmfully influenced by their antics, and it's not like these celebrities try to pass themselves off as role models anyway.
The fact that the series often uses Disney's adaptations of fairy tales as a base (Gaston's not even in the original Beauty and the Beast) really does not help. That and the fact the series uses fairy tales currently untouched by Disney (Hansel and Gretel) and some books that aren't considered fairy tales at all (Frankenstein) is a bit of a Mind Screw.
This led to the sad story of Angel's botched terrestrial broadcast in the UK. Channel 4 bought Angel and decided to broadcast the first season at six in the evening, because, you know, anything with magic in it is obviously teatime fare for kids. Despite extremely heavy censorship cuts, this still led to a formal reprimand from the Broadcasting Standards Council. The last few episodes of the first season, and the whole second season, were consequently shown after midnight with little or no publicity. The third season was bought instead by Channel Five, who treated it equally badly. (The other two seasons have never aired on any UK terrestrial channel.)
Dinosaurs is made by Jim Henson, aired on the Disney-ownedABC and features adorable dino puppets, so it's for kids, right? Technically not. The show has some mild profanity and has some sex jokes, and the last episode was one big letdown (not because it sucked, but because it was depressing).
There's Project Runwaymerchandise aimed at preteen girls. The show isn't for them, due to swearing (most of it censored), adult themes like drinking, and references to things kids wouldn't know about such as A Chorus Line. It doesn't help that Tim Gunn would later voice Baileywick in an actual show aimed at girls, Sofia the First.