That points to an article in eweek that describes a social networking site that you (and your students!) should be aware of. I won't mention the name here - you'll have to read the article. But here's a little of what it does. According to this article, when you sign up for it, it makes you enter your web email account information. That would be a hotmail, yahoo or gmail type account. Then it logs in as you and spams the folks in your online address book with invitations to join that network. And you don't even know it's doing it.