Every statement you make on Google Plus or Facebook is persistent and strongly attached to your real identity through your name. Both services allow you to change settings to make your statements more or less public, which solves some problems. However, participating in public life on the services requires attaching your name to your statements. On the boulevards and town squares of Facebook, you can’t just say, “Down with the government,” with the knowledge that only a small percentage of the people who hear you could connect your statement to you.  But the information is still being recorded, presumably in perpetuity. That means that if a government or human resources researcher or plain old enemy wants to get a hold of it, it is possible.