I also see that this is bitcoin, and the problem is with SR. Sure the site is using bitcoin, but it could just as easily have used USD notes.
The beauty of this is that they *did* choose Bitcoin, demonstrating (in a roundabout way) that its advantages over traditional currency are sound.
Also I was wondering how illegal is SR? They don't actually sell drugs themselves, they are simply an intermediary, matching up traders. SR themselves aren't doing anything illegal AFAIK (please tell me otherwise).
SR is a seller as well as the maintainer of the site, to my knowledge. Many of the initial sales were directly from him/them.