>The few criminals caught via these tools are almost always the low hanging fruit of unconnected crazies
This is true of the criminals caught via FBI counterterrorism's more traditional police work that ends in civilian courts.
It remains entirely possible that the intelligence establishment enjoys some success in penetrating more sophisticated groups, but doesn't write press releases about it (since it will be acted upon with further covert operations to get further into those organizations, or with secret assassinations.)
This is true of the criminals caught via FBI counterterrorism's more traditional police work that ends in civilian courts.
It remains entirely possible that the intelligence establishment enjoys some success in penetrating more sophisticated groups, but doesn't write press releases about it (since it will be acted upon with further covert operations to get further into those organizations, or with secret assassinations.)