This one isn't that surprising either, but it's kind of amusing.
You know those anti-drug ads that the US government films with people frying eggs and driving over little kids while stoned? Think they're actually effective? What? Are you high?
"A Government Accountability Office report on research tracking the impact of the federal government's $1.2 billion anti-drug ad campaign concludes that "the evaluation provides credible evidence that the campaign was not effective in reducing youth drug use, either during the entire period of the campaign [1998 to 2004] or during the period from 2002 to 2004 when the campaign was redirected and focused on marijuana use."
"In fact, during some periods and for some subgroups, exposure to the ads was significantly associated with an increased tendency to smoke pot."
On the other hand, they were less likely to fry eggs, so that's good...