Crowned the best social networking site by Computing Which? Magazine, Bebo is the third most popular website in this category on the web and has recently been bought out by AOL.
The danger:Bebo currently allows users to add their AIM, Skype and Windows Live usernames to their profiles. While many view this as a positive, it acts as yet another way to trace users across the internet. Bebo has also been linked with a string of teen suicides in Wales.
Estimated users:50 million