This is both funny and scary at the same time. A British teen accidentally created a public event for her private birthday party and posted it to Facebook (including her home address and contact info). Within a few days over 20,000 people responded (and now know the girl's address and contact info).
You can read the article here:
Parents, know what your kids are doing on Facebook. Kids make bad choices sometimes (intentionally or not) and Facebook does nothing to protect their privacy. It's definitely a dangerous place for kids.