most child porn and criminal activities aren't distributed/engaged through web sites, if they really wanted to put the lock down on that shit they'd just block IRC and usenet 'cause thats all they're really used for nowadays.
Nah. That might have been true long ago, and they're probably still being used for that purpose, but these operations really take place on encrypted channels. Most of them are simply private servers with fully encrypted hard drives. Somewhere on Wikileaks there's a chilling account of exactly how it's done, and why it can't really be stopped in any effective way, by an anonymous guy who was in the business himself.
edit: here
http://wikileaks.org/wiki/My_life_in_child_porn skip to the section "The technology of today"
