Coming from someone who is on this site a lot.....
We get a ridiculous amount of "scammers" (IMO). Actual scammers as well as people who literally try to throw up 25 posts in the matter of minutes and then are never to be seen from again.
I can think of multiple times just in the last 6 months of Chinese or whatever based companies posting up and advertising their billboard in the welcome section.
Also, with the number of people that buy and sell things that completely screw people over. It does help put a damper on some of that when people have actually engaged within a group.