This lecture was presented at TAM8 by Phil Plait. He's speaking to skeptics on how to present arguments to convince someone that "they're not thinking clearly when they're not thinking clearly". Substitute your favorite scam for each time he mentions alternate therapies, magical thinking, supernatural beliefs, etc.
Dr. Phil Plait: The goal of skepticism
(There was a lot of positive reaction to the talk, but also some criticism.)
Phil Plait's Don't Be A Dick talk at TAM8 Now Online