Yes, there's a reason I'm shouting a bit in that header.
We had a hacking attempt today. Someone attempted to log in to a number of people's accounts. It looks like they were just trying to guess people's passwords, and failing. As far as we know they did not succeed, but we are still looking into it.
Please make sure your passwords are strong.
If anyone starts posting crazy stuff and we suspect their account has been compromised, they will be blocked until it's sorted out. But so far it seems like it was a failed attempt.