When Web sites require people to agree to their terms of service agreements, it is often to prevent children from accessing the site's content. This is supposed to help moms and dads restrict what their kids see online, but it actually has the exact opposite effect, a new study paid for in part by Microsoft reported.

A group of Berkeley and Harvard researchers conducted a study of 1,007 parents in the U.S. with kids aged 10 to 14 years and found 36% of them knew their underage children had joined Facebook. The debate about what it means to have under-13 year olds on Facebook is heating up because the Federal Trade Commission is reviewing the Children's Online Privacy Protection Act.

This piece of legislation is meant to protect children and their data online. The research concluded COPPA's unintentionally undermined parents' online choices about what their kids so online. Because of COPPA, kids lie more about their age, and their parents even help them. The study also found 68% of the parents who knew their underage child was on Facebook had actually helped them create their profiles.

Furthermore, 78% of respondents said there were multiple reasons that make it okay for their child to lie about their age in regards to Web site's terms of service.

Facebook responded by saying they remove 20,000 accounts per day, the study said. And the terms of service isn't the only way Facebook can tell if you might be underage. By watching who you are friends with and the types of content you submit, Facebook might be able to tell if you are underage and delete your profile Of course, that type of activity is just the type of thing that might get privacy activists in an uproar, and could be just another unintended consequence of the the well intentioned COPPA.

Tell us in the comments if you joined Facebook before you were 13.