Stan Marsh, Kenny McCormick, Kyle Broflovski and Eric Cartman head to the local movie theater to see the new film Terrance and Phillip: Asses of Fire which stars the boys' favorite Canadian comedy duo Terrance and Phillip ("Mountain Town"), but when the boys get there, they are refused entry due to the film being rated R by the MPAA, so they pay a homeless man to accompany them. The boys learn obscene phrases from the movie ("Asses of fire") which makes the other kids in town want to see the movie.The following day, the kids begin cursing in class, and they are sent to see Counselor Mr. Mackey, who informs their mothers. Learning that the language was from the movie, their parents force the teachers to enforce a strict dress code banning all types of Terrance and Phillip clothing. While more drastic measures are being taken, Mr. Mackey abandons their previous lesson plans and run a rehabilitation center for the kids to get them to stop cursing ("It's Easy, M'Kay"). Afterwards, the boys and the rest of the children go to see the movie again. Kenny bets Cartman $100 that he can set his fart on fire like Terrance did in the film. Kenny immolates himself and dies when the doctors accidentally replace his heart with a baked potato. Stan, Kyle, and Cartman are grounded for seeing the Terrance &amp; Phillip movie again. Kenny is refused admission to Heaven and sent to Hell ("Hell Isn't Good"), where he is tormented by Satan and Saddam Hussein who are gay lovers. The parents of South Park organize a boycott against Canada and Terrance and Phillip ("Blame Canada"), which is led by Kyle's mother Sheila. The new group of angry mob - called "Mothers Against Canada" - has Terrance and Phillip arrested as war criminals, and when the United States refuses to release the duo, Canada retaliates by bombing the residence of the Baldwin brothers.Sheila, now appointed as the "Secretary of Offense of the United States", and President Bill Clinton announce that the United States will go to war with Canada and will have Terrance and Phillip executed at an upcoming USO show. After overhearing Cartman leading the kids in annoying Kyle with a song degrading herself and admonishing her ridiculous methods ("Kyle's Mom's a Bitch"), she has Dr. Vosknocker forcibly implant a V-Chip in Cartman. The device gives sharp violent electrical shock every time Cartman curses. Meanwhile, back in Hell, Satan declares that if the blood of the two innocent Canadians touches American soil, it will be time for him to rise up and rule the world. Saddam wants to come with him, but Satan is tired of being bossed around by Saddam ("Up There"). Kenny tells Satan to break up with Saddam to which Satan initially agrees, but Saddam wins back Satan with a song ("I Can Change"). Later, Kenny's ghost visits Cartman to warn him of the consequences of executing Terrance and Phillip. After failing to convince their parents, the boys decide to take matters into their own hands ("What Would Brian Boitano Do"). They have a secret meeting to talk about how they can save Terrance and Phillip. They form La Resistance and Gregory tells Stan to recruit a God-hating French expert on covert operations named "The Mole" ("La Resistance").While the troops, waiting for the execution of Terrance and Phillip, are being entertained by Big Gay Al ("I'm Super"), La Resistance and The Mole infiltrate the USO show, but The Mole is discovered by Sheila and the guards, and he is killed by the guard dogs after Cartman fails to deactivate the alarms ("The Mole's Reprise"). The remaining three boys attempt to warn their mothers and the army about what will happen if Terrance and Phillip are killed, but they instead laugh at them, and Mr. Garrison throws the switch to the electric chair. A large Canadian force attacks the base and a massive battle ensues between the two armies. In the confusion, the boys are able to free Terrance and Phillip, though Cartman's V-chip begins to malfunction from the electric shock. The other mothers, seeing the destruction their "Mothers Against Canada" movement has incited, decide to call it quits and head off to look for their children. After being stunned by an explosion, Stan has a hallucination and is visited by "The Clitoris" which tells him that all he needs is confidence if he wants to win Wendy's heart and also reminds him about what's more important: saving the world.Stan leads the kids to find Terrance and Phillip who have been cornered by the US army. La Resistance forms a human shield while Kyle tries to persuade the army and his mother against killing the two, stating that he wants her to stop fighting everyone and deal with him. However, Sheila refuses and shoots Terrance and Phillip, which fulfills the prophecy and results in Satan, his minions, and Saddam rising from Hell and attacking both Canadian and United States armies. As a result, Sheila now regrets everything, even though she wanted "to make the world a better place for children". Saddam immediately tries to usurp Satan's authority, demanding homage and announcing his intent to rule the world himself. Cartman is able to hold Saddam off by using his malfunctioning V-Chip to generate massive blasts of lightning every time he curses. With Kenny's encouragement, Satan finally gets rid of Saddam by casting him back to Hell and getting impaled on a sharp stalagmite. Satan then grants Kenny a wish in repayment: Kenny asks for everything to return to how it was before the war, even though it means he'll go back to Hell. He takes off his hood to say goodbye to his friends, revealing his face and voice for the first time. All the other deceased characters are brought back to life, the Canadians and Americans become friends again, Wendy becomes Stan's girlfriend again and dumps Gregory (she never really liked him), and everything returns to normal in South Park ("Mountain Town (reprise)"). Instead of returning to Hell, Kenny ascends to Heaven due to his act of sacrifice, where naked angels are waiting for him and he is granted a halo and wings.
Output: Question: What curbs Cartmans use of profanity?, Answer: V chip