It's exactly what it sounds like: someone on my friends list told me on Skype that they quit Gaia because they had been dealing with a lot of harassment from users and staff on the site. They'd been banned, I don't know how long ago, since I just figured it out today. lol Something about TOS and telling people to not do it but do it offsite. I guess that wasn't allowed, but not even I knew that. Ah, well.
In one case, somebody had tried to hack into their email address - or had successfully done it, since a friend of theirs had messaged them saying that they didn't want to talk to them anymore and police had called to confirm a kind of restraining order on them. When my friend went to go check who had really been on their account and harassed his friends, he found that an IP address that led back to the computers on Gaia.
And sometime later, they had been attacked in their home; choked unconscious. Then they found out who did it and saw that the person was boasting about how they knocked him out / offed him.