"AN: And there you have it folks. Let me know what you thought. Disturbing? Funny? Moving? Or maybe all three. I don't even know if this would make it to an R rating. Fuck, damn, cock, balls, shit, bitch, hell. There, now it's an R fic."
Hint: If Snape has uttered five lines and already used two obscenities, and the situation is anything less shocking than The End of the World as We Know It or Harry Potter becoming his direct superior (or possibly the line "She hasyour eyes"), you probably don't know how to write Snape.
The Girl Who Lived series has a lot more swearing.
There's Bert/Ernie slash in which the dialogue is composed mainly of swearing. As mentioned, it is extremely jarring to hear Sesame Street characters swear for no reason other than sounding "mature". Guess they picked up some habits from their friend, The Count.
So much Warrior Cats fanfiction includes swearing, even though the books don't. This isn't because the book characters don't swear, but because they swear using feline profanitites. So it seems really out of place when, in a fanfic, someone yells "shit!" or calls someone a "bastard" while in the original novels they would have used "fox dung!" or called them a "fox-hearted traitor".
Probably the best example of this in fanfic would be a oneshot which features a kit dropping an f-bomb in every line of dialogue. That's right, a kit.
Hunting The Unicorn subverts this. It's a Glee fanfic written in a very traditional style, but the Warblers swear a lot more than they do in canon. It seems more due to the fact that they're a group of teenaged guys who take everything quite seriously rather than an attempt to make things more adult, and they mostly use Precision F Strikes that are Sophisticated as Hell. In fact, the author rates it Teen instead of R, and the most she does is give a warning for people who dislike heavy swearing.
Reconciliation has Hanako using quite a bit of profanity in her first-person narration, albeit none in her actual dialogue. Other characters' use of profanity is more reasonable; Akira uses some profanity, and Lilly, as in canon, limits herself to a single Precision F-Strikeafter her husband Hisao's funeral.
A lot of YouTube Poop gets laughs by making cartoon characters swear profusely, though most of the time the swearwords are bleeped because the characters didn't swear in the original show and it's not easy to find them saying things like "pingas" that can be clipped out of context.
This is particularly common among the Fire Emblemmodding community. The Fire Emblem games don't swear very much or very strongly at all (the occasional hell or damn, at worst), but mod writers tend to "spice things up" by throwing all sorts of strong swears into the dialogue. They generally have little reason other than "people swear when they're angry".
Pokémon hackers are about as bad. In fact with them it's even more noticeable, since the Pokémon series has no swearing in canon, anime or games. As mentioned below, Pokémon Quartz is a good example.
It seems to be assumed that because he's an angry, rapist killing, former street kid, Jason Todd must speak almost entirely in profanity. In fact, fan fiction's assumption that if you're poor, you swear constantly, can be quite insulting.
One reason why The Angry Video Game Nerd isn't around in TGWTG fanfic much other than when he's paired off with the The Nostalgia Critic. Trying to write his dialog and making it not this trope can get really obnoxious both to write and read.
There's a sizable number of fan translators who think that any Japanese dialogue written in a rough or slangy manner must contain at least one curse word and/or crude idiom when translated into English. This isn't quite Spice Up the Subtitles, since it's rarely done due to lack of practice and usually the gist of the sentence is unchanged.
In Battle Royale, a good amount of the cast swears at least twice. While the novel did include a few curses, the manga exaggerates it a bit to the point that a character may say a sentence that's mostly just swears.
Ed's general portrayal in fanfiction. Yes, fanficcers, he does swear, but not so much that every second word out of his mouth is 'fuck' or variations thereof. This is especially silly considering most of these fans probably got into FMA via the English dub, where Ed's voice actor prefers not to swear unless he thinks it's absolutely critical for a scene.
Notable, and possibly subverted, in the official Brotherhood english sub that the swearing is usually mild, with the F-bomb only used for three particularly tense or dramatic incidents near the end of the show.
Early episodes of Funimation's One Piece dub on DVD often had rather excessive amounts of profanity ("bastard" is particular is really overused). It gets better after a couple discs; it simmers down to the occasional "bastard" or "I'm gonna kick your ass!"
Somewhat justified with the early episodes, especially Sanji's introduction episodes, because his Catch Phrase is commonly translated as either "shit" or "crap."
Another theory is that the swearing was meant to separate Funimation's translation from the infamously kiddie 4Kids Entertainment version.
On the subs for Episode 432, the inmates' nickname for Magellan is "Shit Man" (likely derived from his spending hours every day in the bathroom with diarrhea), and they say it over and over in that scene.
Initial D: When Keisuke encounters Takumi in episode 1, when he sees the car he's driving, Keisuke goes, "An AE 86? No fucking way!" The official dub and sub translate it to, "That's an AE 86. You got to be kidding me!" Aside from that, with the exception of Bunta encouraging Takumi to beat the pants off a smartass kid, the translation is pretty accurate.
Ultimo scanlations often use quite a bit of foul language; Vice uses "fucking" five times in one page and Present!Yamato often swears, too.
Justified in that his character really doesn't care about anything or anybody outside of being a superior fighter, which makes his potty mouth all the funnier when Neliel throws his and her own Cero back at him and all he can say in reaction is "Aw... shit!"
Vita tends to get Obligatory Swearing in Lyrical Nanoha fan translations, fanfiction and even the A's dub, as a result of often using "Kuso" and having a fairly rude way of talking. (like when she screams "WHAT'D YOU SAY, BITCH?" at Nanoha in chapter 7 of the manga)
Bakuman。 fan translations sometimes have this, and as of Volume 3, the Viz translation is moving toward this. It (and some fan translations) has Takagi calling a character in the in-universe series St. Visual Girls' Academy who coldly brushes aside Azuki's character's Love Confession a "bitch", and Fukuda complaining about Yujiro being "half-assed" in not making Eiji meet with him, and Yujiro accusing Yoshida of thinking himself "hot shit" over Otter 11's popularity.
The fan translation of the Metroid manga contains six swear words in the first chapter alone.
In Mai Hime, Natsuki and Nao's dialogue often contains profanity in fan translations. One of the more extreme examples is Nao telling Haruka to "shut the fuck up" in Chapter 18 of the manga.
In a fan translation of Cardcaptor Sakura, the phrase Sakura used to make Touya believe Kero was a puppet and she was doing a comedy routine was "What the hell? What the hell?". The Tokyo Pop translation used the more common "Fuggedaboutit" phrase.
The old Anime Labs Dragon Ball Z fansubs went way overboard. One of the most infamous examples, a line uttered by Vegeta after having his house destroyed, reads "You fucking bastard! You dare to destroy my house! Now you've really pissed me off! Fuck you!" in their translation, but the official (and much more accurate) FUNimation translation reads as "Smash up another man's house, will you?! I'm in a foul mood today! Don't come too close or you'll get burned!". Another golden line is "Come out, you candy-ass faggot!", corrupted from "Where are you!? Come on out, you coward! Show yourself!".
In one translation of the Puella Magi Madoka Magica manga, Kyouko uses Cluster F Bombs when she gets angry. For example, after wounding Sayaka in their first fight, she says "What the fuck was that about? You'd better keep your shit together, pisshead." (emphasis theirs).
The official manga translation of To Love-Ru in Spain has a lot of swearing for no reason, especially from Rito, something about as Out of Character for him as it gets. The best example is one line with him saying "What's going on?" in the original becoming simply "Fuckers!", not even "What the fuck is going on?" or something, just "Fuckers!". Since the translation also has quite a bit of Gratuitous Japanese, it gives a "bad scanlation" vibe.
Haruhichan's English Dub release contains swearing from Haruhi, Kyon, or Achakura. For example, the quote "I KNOW I SHOULD, SHIT HEAD!" marks one of the times Achakura swears, with that quote being said in Episode 15.
In the manga version of Girls und Panzer, there's some jarring profanity in scanlations, such as when Miho is first asked to be commander.
Miho: No, no! No fucking way!
In the manga version of Kingdom Hearts, there's some profanity sprinkled into scanlations; first it starts out in early chapters with words like "crap" and "freaking", no worse then what you'd hear on Cartoon Network, but then the language goes up to "damn", "hell", "bastard", and even one use of "effing." It's quite surprising considering this is a manga based off a children's franchise with Mickey Mouse, Goofy, Donald Duck, etc. in it. In the official Tokyopop and Yen Press volumes, rated "all ages", there's no profanity at all.
In the European Spanish translation of the Death Note manga by Glénat, it's pretty common to find (along with some local expressions sprayed everywhere) profanity that wasn't in the original. Weirdly, most of the profanity appears in LightYagami's lines.
Countdown to Final Crisis had Mary Marvel (normally the cute kid sister of the DC Universe) go evil, then get a grip on herself and turn good... only to go evil again at the very end. In the final issue, she explained just who she was: "I'm Mary Damn Marvel."
Invoked in-universe in Star Trek IV: The Voyage Home. Kirk is called a dumbass by a cabbie for jaywalking in front of the cab. Kirk picks up that profanity is the norm, so he starts using it. Spock tries.
The Hungarian DVD dub of the movie is infamous for this (among other things). Ironhide, for instance, calls the Decepticons "szarháziak" (sons of bitches) twice, while Grimlock calls Blurr a "seggfej" (asshole). Though the "Oh shit!" line was cut from this version.
OFWGKTA is this trope played straight. Tyler is a particularly prime example, utilizing the word "fuck" in just about every bar, while also having a penchant for dropping the "faggot" bomb and referring to women as bitches and cunts.
The anectdote listed above under Anime & Manga also applies here. It's not too bad in most cases, but when you're playing a fan translation of a Famicom/NES or Super Famicom/SNES game even such words as "damn" or "hell" can be quite jarring to see, considering most games of those periods had a Nintendo-mandated Gosh Dang It to Heck! hovering over them, (Granted, there were a few occasions where they slipped up.)
Among other things, the game Shadow the Hedgehog was infamous for having the title character (and even a few characters like Sonic himself) gratuitously using the word "damn".
"Argh! Fucking kid! You send my plans down to the WC!"
Guilty Gear: "I always knew you were a shitty king! You can't even protect yourself!"
The House of the Dead: Overkill has gone on record for having the most instances of the word "fuck" uttered in a game. The first words spoken are "Whazzup, motherfucker!"
Isaac Washington uses "motherfucker" so often that the one time he conspicuously doesn't gets a Lampshade Hanging.
The game even made it into the Guinness World Records for being the most profane game ever. However, it was beaten a year later by Mafia II. Overkill's Updated Re-release took the title back, so whatever.
The Metal Gear series usually has very little swearing, just the occasional "damn" here and there. However, in Metal Gear Solid 3, one of the radio conversations you can have is about a nightmare Sigint had about a giant walking turd that turns everything it shoots into shit.
Download, a relatively obscure PC Engine shmup, has swearing in its game over messages: "I cannot fuck up for this" and "Shit, is not this a great beginning."
The original Max Payne had only mild to moderate swearing, the worst of which being the odd "goddammit." The sequel dropped this trend.
The DeJap translation of Tales of Phantasia has this. This actually caused a bit of Mis-blamed when the game was given an official localization, like how the translators allegedly "censored" the adult humor that was never actually in the original text itself.
The original English release of Tactics Ogre Let Us Cling Together, translated by Atlus used practically every swear word in the English language short of the f-bomb. Anti-Hero Vice was particularly foul-mouthed for somebody on the good guys' side, as one of the first things he says in the game is to call the hero's sister a bitch (though with good reason). It is generally agreed, though, that the rough language did drive home the point that War Is Hell and can bring out the worst in people. The PSP retranslation which was helmed by Alexander O Smith cut out almost all the swearing.
Final Fantasy VII has a similar issue. Almost any interjection made by a frustrated character was translated as anything from "dammit" to "shit", even when the characters weren't even swearing originally (e.g. frustrated grunts such as "くっ" often became something like "Shit..."). Granted, it's one of the darker installments in the series. This is probably due to the localization being handled by Sony USA instead of Square themselves, as later Final Fantasy games have much more PG-level language.
The Hungarian dubbing of King of the Hill had great fun with this. That aside, surprisingly many dubs of cartoons meant for kids also use the word "shit" rather arbitrarily. Then again, it seems to have become a relatively tame word these days, as it's no longer bleeped-out in most Hungarian media, similar to "Crap".