"Bass to Mouth" is the tenth episode of Season Fifteen, and the 219th overall episode of South Park. It aired on October 19, 2011.
The students of South Park Elementary are the victims of a new gossip website. An elusive hacker has somehow gained access into the student's confidential phone calls and e-mails and is posting all their juicy stories. The boys and their friends are shocked when they discover the identity of the hacker.
A new gossip website named Eavesdropper gains popularity among the students of South Park Elementary, by posting embarrassing information gleaned through unlawful access to the confidential phone calls and emails of the school and its student body. While Cartman is elated at the embarrassment of one such student, Pete Melman, who defecated in his pants while in class and had to have his mother to bring him a clean pair of jeans, the school administrators are displeased. Recalling that a year earlier, another student, Corey Duran, suffered a similar incident, and subsequently committed suicide after Cartman spearheaded a campaign of ridicule and torment against him, Mr. Mackey, Principal Victoria and Mr. Adler ask Cartman not to let the same thing happen to Pete. Though Cartman initially rebuffs their request, telling them that it is impossible to contain such an incident, they tell him that if Cartman sees Pete through this ordeal, and turns public opinion around in his favor, they will make it worth Cartman's while, which piques Cartman's interest.
Cartman engineers a repeat of the incident by giving another student, Jenny Simon, cupcakes laced with laxatives, causing her to defecate in her pants in the middle of class. After Jenny attempts suicide, Cartman is pleased, feeling that he prevented Pete from doing so, but the administrators angrily explain to him that they did not want anyone to attempt suicide. After they tell him that he must fix this or forfeit that which they promised him, Cartman devises a plan to reward the student body for their recent state exam scores with a pizza party, where they will feed the students pizza laced with laxatives and Arby's horsey sauce, thus causing the entire student body to suffer the same misfortune, diffusing the torment experienced by Pete and Jenny. Although initially outraged at Cartman's idea, they realize they do not have a better one, and decide to implement it.
The student body continues to enjoy Eavesdropper, except for Kyle, who is offended at the invasion of privacy committed by the site. Though Stan does not initially share Kyle's outrage, he has a change of heart when the site publishes information from a private email of his, whose revelation angers his girlfriend, Wendy. Rallying the student body against Eavesdropper, the students discover from the IP addresses of the site's postings that they are being made from the school's music room, where they discover a rat with a blond head of hair at a computer terminal. The rat escapes, though they discover that his name is Wikileaks.
Meanwhile, in the bedroom of a young boy, Vernon Trumski, Lemmiwinks, the old school gerbil from the episode "The Death Camp of Tolerance", is visited by the ghostly Frog King, who previously guided him to safety in that episode. The Frog King tells him that Lemmiwinks' brother, Wikileaks, is spreading terrible rumors based on hacked emails. When Lemmiwinks exhibits reluctance to confront his own brother, the Frog Prince and his colleague, the Sparrow Prince, send another spirit guide, the Catatafish, to Stan and his friends, instructing them to go to Trumpski's house and take Lemmiwinks.
As Cartman and the administrators prepare the pizza, the administrators uphold their end of the agreement by presenting singer Selena Gomez to Cartman, and then beating her up, much to Cartman's delight. Their actions are observed by Wikileaks, who announces to his site's visitors that he will soon reveal his biggest story yet. As the public reacts to this announcement, the school administrators, worried that they will be fired when their plan is exposed by Eavesdropper, devise to distract the public with an even bigger story, that of a student's suicide. Mackey decides that they will engineer Cartman's suicide by literally throwing him under a bus.
The children procure Lemmiwinks from Trumpski's home, and take him to the school by bus, but on the way there, the school administrators throw Cartman in front of it, and declare that Cartman committed suicide. The students and administrators continue together with Lemmiwinks to the school, where he confronts and kills Wikileaks. Though the content of Wikileaks' tabloid website is deleted, Lemmiwinks is devastated at having to have killed his own brother. Cartman, who suffered only a broken arm and leg, gets revenge on the administrators by giving them laxative-laced cupcakes, causing Mr. Mackey to defecate explosively in his pants, propelling him through the hallway and into the ceiling.