I've started using Facebook recently and I've set up a few groups for work. We're a Translation and Interpreting company so to get more linguists to register with us I set up a group. It's worked really well. If you're a linguist on Facebook please join.
While I was looking for other related groups I found this quite scary one for United States Intelligence Community. It's an open group so anyone can join. What I can't tell is if it's a spoof or not. It looks pretty official and if it is maybe you should be nervous.
The web is a really weird place sometimes!