I'm not saying that wouldnt happen, but it would stop them doing it after a 7 post count with them introducing themselves as a newbie, replying to all the "welcome" posts, then the "what mods do I do first" post that comes after.
If theyre are 200 posts from someone and them scamm some person, there might be some info in that 200 posts that could incriminate them....

I have even sold stuff for mates on here because I know I'll get the parts shifted quicker than them with theyre low post count.