Study: Abstinence May Lead to Risky Behavior
Since I've first read the article, they've changed the article title to "Abstinence Pledgers May Risk STDs," which makes a little more sense.
You know, I'm am all in favor of kids receiving abstinence education, but I am very skeptical of how effective it can be when every other stimulus the child receives tell's him how great casual sex is. Most kids get their sex education outside of the classroom, and what they learn in school comes off as incredibly lame, no matter what is taught or how it's presented.
If parents are not with their kids after school, if they are letting them watch whatever they want on TV, listen to whatever they want on the radio, and view whatever they want on the Internet, if they let them hang out with the wrong kids in unsupervised situations, and if they are not teaching their children about the inestimable value of their bodies or how to use them to glorify God, then an "abstinence program" at school is going to be of practically no use, unless it manages to somehow scare some good sense into them.
If you are letting your children be raised within or by pop culture you are setting them up for a lifetime of big problems.

1st runner up: "Use of sunscreen leads to increased skin cancer." It was a TV news report about 15 years ago. At the end of the report, they revealed that people who use sunscreen tend to spend more time in the sun than people who don't use sunscreen. Brilliant!