How Your Username May Betray You - Technology Review
Worth a read. The gist? Scammers can cross check profiles on various sites (assuming you use the same username on all of them) and use it to build their database of "suckers." Of course this goes without saying, make sure you use different passwords for all your profiles online to keep your personal information safe. Need help with all those profiles and passwords? Use LastPass and you won't regret it.
How Your Username May Betray You - Technology Review.