While this is true to varying degrees, you'll note that I said discreet. An intrinsically anonymised version of this would basically allow people to more or less openly distribute read-only keys. Torrenting can be used for much dodgy stuff, but if you want to catch large amounts of people distributing this stuff, all you need to do is connect to a swarm and start writing down IP addresses. The difference between this and distributing pirate copies of Game of Thrones is that while governments around the world have wildly varying degrees of how seriously to take copying GoT (That are normally in the lower spectrum of serious) the response to CP is pretty much unanimous the world round. While people could do this same thing in other, more manual ways, it's less than ideal for than something that will automatically always be there, because manual processes make for mistakes, and one mistake and you've got a good chance of being on somebody's list.