History YMMV / PennAndTellerBullshit

* ValuesDissonance: Considering that P&T often deal with the extreme fringe of many ideological groups, this comes up a lot. For instance, the duo believes violence is only justifiable in defense of self or of innocent people (and they fall just short of total pacifism), so much horror and disgust ensues when interviewing someone who thinks violence is excusable to advance political causes, like environmentalism or animal rights.

** [[FamilyUnfriendlyDeath The descriptions of botched executions]] in the Death Penalty episode. Pre-lethal injection anesthetics not working properly, hanging where the victim's neck doesn't get snapped (leading to a more drawn out and painful death by strangulation) and the electric chair with the victim's flesh melting off, not much different from a certain execution in ''Film/TheGreenMile''. Not to mention the medieval execution they mentioned on the side.

** Their episode on vaccinations was incredibly important and brought to light some info that is much needed about vaccinations and autism. But as of February 2015 the anti-vaccination movement has seen a return and measles are coming back.

** The shows libertarian viewpoints become this after Penn Jillette decided to reject libertarianism (specifically the ideology's right-leaning aspects).

** Paul Watson from ("Endangered Species")

* CriticalResearchFailure: Sometimes occurs as a result of the duo's strong opinions overpowering objective evidence.
** The study they used as a reference for the second-hand smoke episode was a corporately-funded exercise in LiesDamnedLiesAndStatistics, and had already been discredited when they made the episode.
** In the "Taxes" episode, Penn claims that UsefulNotes/AlCapone was sent to Alcatraz for tax evasion in 1932 because the Justice Department couldn't prove his more serious crimes, and cites this as evidence that the government can always use tax evasion as an excuse to lock someone up if they can't prove that they've done anything wrong. Except that's not what happened to Al Capone--at all. He was convicted of tax evasion ''because'' he ran a large criminal syndicate, not in spite of it: he failed to hide the income from his criminal activities from the government, and was busted for failing to pay income taxes on it (since illegally earned money is still subject to taxation).
** The episode "Holier Than Thou", which attacks popularly revered figures, uses some pretty selective evidence to paint its subjects in a darker light. For instance: its segment on the 14th Dalai Llama ignores many aspects of his life in its attempt to paint him as a wannabe dictator, such as how the Central Tibetan Administration (the Tibetan government-in-exile supported by the Dalai Llama) is democratically elected. Most of Penn and Teller's criticisms of the Dalai Lama are aimed at the former institution of Tibetan serfdom rather than the man himself; they neglect to mention that the 14th Dalai Lama has never advocated for the return of serfdom to Tibet.
** The episode "Recycling" makes the argument that recycling does not work and thus does not deserve government funding. It cites a 1989 paper which argued that recycling paper produces more pollution, but neglect to mention that subsequent studies found that recycling actually produces less pollution that originally thought. Penn and Teller [[https://www.youtube.com/watch?v=57r5xEsvftM admitted]] that they changed their minds after the episode was produced.

** The shows libertarian viewpoints become this after Penn Jillette decided to reject libertarianism.

* WhatAnIdiot: Some time after an episode debunking the use of chiropractors (not all forms, mind you; the main expert on their side was himself a chiropractor), a group of chiropractors ''bought tickets to their live show'' just to tell Penn and Teller that they were offended by the episode and are boycotting them.

* RetroactiveRecognition: Since the show, being quasi-documentary in nature, went out of its way to find people in the public eye willing to talk about a particular subject the show was covering, it's likely you'll recognize someone who appeared on this show on other news or information programs (Jack Thompson from the "Video Games" episode, Richard Cohen from "Family Values", Roy Moore from “Bible: Fact or Fiction”, Dennis Prager from "PETA" or Paul Watson from "Endangered Species" are particularly visible individuals, not to mention Sheriff Joe Arpaio). Given the show, you could call this trope, "Hey, it's that asshole!"

** The episode "Holier Than Thou", which attacks popularly revered figures, uses some pretty selective evidence in an attempt to paint its subjects in a darker light. For instance, the description of the 14th Dalai Llama ignores many aspects of his life in its attempt to paint him as a wannabe dictator, such as how the Central Tibetan Administration (the Tibetan government-in-exile supported by the Dalai Llama) is democratically elected. Much of Penn and Teller's criticisms of the Dalai Lama is aimed at the former Tibetan serfdom, rather than the man himself, and the 14th Dalai Lama certainly did no make any comments wishing for the return of serfdom to Tibet.

** In the "Taxes" episode, Penn tries to cite UsefulNotes/AlCapone's infamous 1932 conviction as evidence of how scary the American tax system really is, arguing that Capone was sent to Alcatraz for [[ConfessToALesserCrime "tax evasion"]] because the government couldn't prove his more serious crimes--implying that the Feds can always use tax evasion as an "Ace in the Hole" if they ''really'' want to bust someone, but can't prove that they've done anything truly wrong. Except, if you know anything about Capone's trial, you'll know that tax evasion wasn't just a random crime that was unrelated to his criminal activities: he had vast sums of untaxed income because he ran a lucrative illegal bootlegging enterprise that he was trying to hide from the government, and his unpaid taxes were used as evidence of that.

** The episode "Holier Than Thou", which attacks popularly revered figures, uses some pretty selective evidence in an attempt to paint its subjects in a darker light. For instance, the description of the Dalai Llama ignores many aspects of his life in its attempt to paint him as a wannabe dictator, such as how the Central Tibetan Administration (the Tibetan government-in-exile supported by the Dalai Llama) is democratically elected.

* {{Anvilicious}}: Although some would argue that SomeAnvilsNeedToBeDropped.

* NauseaFuel: The "mucus mask" bit, with the snails that wind up clustered around people's eyes.

** That snail "mucas mask" gag from the first season became an actual fad about a decade later. Rendered down instead of applying the snails directly, but the justification is identical.