It would be fairly easy to get IP addresses and track people down. I still get a little nervous that a site like this could eventually be subject to a subpoena /raid and cause a one time mass bust. Kinda like when they tried to stop music piracy by busting 10 of 10,000,000,000 people stealing songs just to send a message.
I'm a newb to this plant growing hobby but have extended mycology experience growing fungus and have been on certain grow forums for years. I have always been skeptical but have never heard of anyone getting busted because they posted at a forum. Though I have heard of people getting further busted due to forum posts found on seized computers.