Imagine the IRA, except they can fly, go invisible, or simply step into a phone booth or fireplace and vanish, and had an entire other dimension they could disappear into where they could be self sufficient.
Technology means nothing if you don't even know who you enemy is.
Heck, they can mind control people, wipe their memories, or take a potion and assume their identity. It would be like fighting the Face Dancers from Dune if they were all trained in The Voice.