The thing is, Sirius has already seen this and the heroin store threads and has chosen not to lock/delete them.
That's maybe because there are not many such threads and there is no official policy or set of rules on this forum yet.
But it doesn't mean that somebody (Sirius) can't make one.
If there is one-two threads, that is not a problem. But when such threads start showing up in hundereds, this may change.
Also, pornography is not illegal in most of normal countries. So it's not a big thing.
Just wait until people will start selling drugs & arms here. Hell is gonna break loose. That will definately catch the attention of governments -
and the website will be closed faster than you can spell "censorship".