Skepticism, and Bullshit in Bullshit by Penn and Teller
The second, and far worse problem with the show is that some of Penn's bullshitting is in fact bullshit itself. So far I've only seen roughly ten episodes, but the episode where they claim there was no scientific evidence that showed second hand smoking was unhealty was simply bullshit. According to the Robert Todd Carroll, the author of the Skeptic's Dictionary, he as well as Penn and Teller were lead to trust the standards of risk assessment as promoted by the tobacco industry (led by Philip Morris) and their Republican generals like Jim Tozzi.
Also the episode on the environmental movement had some strong elements of bullshit. Surely the movement attracts alarmists and many of the movement's claims are bullshit, but the general concern of global warming and its consequences among academics is genuine rather than a tool for another round of research funding. Carroll states that this episode "is based on these same questionable standards pushed by Republican leaders for their corporate donors whose main interest is the deregulation of industries and products rather than public safety or health. This approach fits well with P&T's libertarian philosophy but it is essentially dishonest and does nothing to promote the view of skepticism as healthy critical thinking."
In fact this abuse of pseudo-skepticism as an opinion altering tool for industrial deregulation is what I consider the greatest threat to Skepsis and CSICOP. The crackpots with their occasional legal threats are just bullshit.
Also the episode on diets threw more bullshit than necessary. Of course there's an abundance of bullshit in the diet industry, but it seems the late Dr. Atkins did have a positive impact on the science of obesity research after all. Despite being used to treat some forms of epilepsy since 1920's has no-one ever shown his diet to be unhealty. Furthermore, numerous recent studies have shown the effect on both weight as well as blood lipids are generally better to the "prudent" generally recommended diets.
But I can't deny the entertainment value of the show even if the background research seems scarser than Teller's lines. Maybe some day they'll air a self-critiquing episode - that would likely be the most interesting episode of them all. Until then, my dear readers, you should regard Penn and Teller's Bullshit! as manure or politics rather than true skepticism or good journalism.