While we like to romanticize these groups, they often have ulterior motives in getting users to the site. Pushing ads from less-than-reputable ad-sources, and having a section with binaries where admins can push malware laden programs/games/files to increase the size of a client's botnet.

The model is that as users become more comfortable on the site, they eventually browse to the more dangerous categories and download programs/games/cracks/etc...

I wrote a blog post about a deep dive I did on one site, and showed that the admins were seeding malware in program downloads.

Suffice to say, when I reported the admins, other admins banned my account on the site and IP blocked me.

I actually ended up taking the blog post down because they started attacking my domain, and even Google blacklisted my domain because I had snippets of the malware code posted (I guess I should have used images instead of code). I was younger and just tinkering with security research anyway.