I found out about this from The Skeptic's Dictionary Facebook posting. The Centre For Inquiry Canada started their "Extraordinary Claims" advertising campaign a couple of days ago, on the 19th. Here is a video from CFI which explains the basis of the message:
Educational initiatives like this are important and meaningful, and the fact that the campaign pays tribute to the late Carl Sagan doesn't hurt, either. On the assumption that critical thinking can't be started too early, Skeptical Dictionary has a list of resources for younger readers that all geek parents (or the parents of geek children) should find useful. Applying the principle of seeking extraordinary evidence for extraordinary claims is a great place to start.