Isn't it kind of the POINT of a darknet that nobody can trace who's who? Sounds to me like the system is working as designed.
Yes, it will be used to break laws. But that's when you break out the actual investigative skills instead of relying on tech work and unrestricted wiretaps.
#aph on AnonOps ran into this same problem. Their solution was to continue trying to break into the sites and attack the visitors with trojans, confirm they intended to view child porn (I guess checking to see if there was a large amount of it on their machine) and exposing whoever they could, knowing they're going to miss people that are fully patched or not on a machine that the malware is compatible with or what not. The channel seems pretty dead now though, anything beyond one or two steps is beyond most of them.
If all else fails, lower your standards.