But kids aren't the only ones using these networks and taking risks. Adults can get into trouble, too, if they're not careful.
The vast majority of social networkers and bloggers are adults. Even MySpace — which is extremely popular among teens — is mostly used by adults. Another popular site, facebook.com, is mainly used by college students, who are typically older than 18.
(Disclosure: I help operate a non-profit Web site called blogsafety.com which is funded in part by social networking companies including MySpace, Facebook and Xanga.)
The vast majority of people who use traditional blogging services such as Blogger, TypePad and Word Press are also adults, using these services for everything from professional networking to personal expression.
For adults, the risks include getting in trouble at work or with the law, financial risks, risk to reputation, privacy risks, stalking and — if you get together with someone you meet through a blog — the possibility of molestation, robbery and other attacks.
Perhaps the biggest risk for adult bloggers is getting in trouble at work. A report by the Employment Law Alliance estimates that perhaps as much as 5 percent of the American work force is maintaining online personal diaries but only 15 percent of employers "have a policy directly addressing blogging activities."
Of those that do, according to the report, "62% say the policy prohibits posting any employer-related information, 60% say the policy discourages employees from criticizing or making negative comments against the employer and 58% say the regulations deal with all blogging, regardless of content."
There are numerous reports about bloggers who have been fired or disciplined for things they've posted on their blog. The most frequent examples involve employees who write about their employers. Even Google, a company known for progressive employee policies and the operator of blogger.com, has reportedly fired at least one employee for criticizing the company in a blog, according to a story on news.com.
Bloggers at Microsoft and the social networking site Friendster have met similar fates, according to news accounts. Ellen Simonetti, also known as "Queen of the Sky," said she was fired by Delta Airlines for famously posting what someone at work apparently considered "inappropriate images" of Simonetti in her flight attendant uniform.
There are also reports of college students who have been disciplined or even expelled from school as a result of their blogs or Facebook profiles. In 2005, the president of Fisher College Student Government Association was expelled from the Boston-area college for posting a critique of a campus police officer on the student's Facebook profile, according to the Boston Globe.
Even people who work for media companies may be limited in what they can say. There are broadcast and print outlets that restrict what editorial staff and other employees can say in their private blogs as well as on any company sponsored blogs.
Whether you're a student or an employee (or both), it's a good idea to see if your company or school has a policy about blogging. If you're not happy with that policy you might want to bring that up in an appropriate manner, but violating it could have severe consequences. Even if there isn't a policy, you could still wind up in trouble if you report something on a blog that offends someone in charge.