This episode was BULLSHIT!
Some of the previous episodes have been informative, and served to highlight the all too common human capacity to be duped by individuals or movements that play on all the right psychological vulnerabilities, resulting in the victim being sucked into a tissue of lies. In this, I applaud Penn and Teller's attempts to light a spark of awareness and critical thought in people, they did not do this in the conspiracy theories episode however.
This episode was poorly researched and used as examples of the typical "conspiracy theorist", only the most "crazy" and nebulous characters they could find (often in appearance as well as ideas). This served the underlying agenda of the episode, an agenda which was summed up in Penn's all-encompassing opening statement, "Conspiracy theories are bullshit!"
Such a statement categorizes a very wide and diverse field into a singular, one-size-fits-all mold and is analogous to saying something like, "All music is crap!" just because you don't like one particular style. Now, if they had contrasted the "crazies" they had on the show with many of the very hard working and serious conspiracy researchers that are out there, I would not be writing this critique, but as it stands, Penn and Teller have a public voice that reaches far more people than almost any of these individuals, and what is more, it is a voice that utilizes the techniques of modern gimmickry, showmanship and lowest-common-denominator emotional appeals (such as insults and in one case, even an incitement to violence against anyone who believes these theories!). As such, even being the iconoclastic media icons they usually are, the very real possibility exists that their trusting audience will accept their presentation as representing the entire field, and taking their word for it, never delve into a realm of knowledge that very often serves as a vital counterpoint to the gestalt group-think mass media who all too often play the role of government lapdogs and propagandists in a world that desperately needs the truth.