You may not understand the way the dark web works, but unlike the regular Internet, it's completely decentralized and almost completely anonymous, unless you make security mistakes.. so unlike the regular internet where I government can simply subpoena whatever company runs that web pages servers to have it taken down or taken over, the dark web isn't like that. It takes a hell of a lot more investigating and, depending on how good the security is on the dark web site, it could take years for them to find a way to gain control over it and bring it down with arrests.  Not to mention they could probably shut nearly all of them down fairly quickly, but it's worse than Medusa... a hundred would pop up every time you took one down. That does absolutely no one any good, especially the children or victims. A lot of times agents try to go undercover and attempt to gain favor and trust with admins of some of these sites and if it all possible eventually become admins and moderators themselves so that they can gain access to the site that way and gain access to enough information to possibly start identifying some of the customers or even other admins or owner.  Just taking a site down is completely worthless because they can make mirrors and pop right back up seconds later. They have to work the case until they can actually make mass arrests with enough evidence to get convictions to stick.