Half right
To be honest, all they should have been able to do him for is the "conventional dumpster diving and mail theft techniques" (plus anything that he did with the IDs after he had them).
If someone share something with a P2P program, someone else will get a copy of it. That's not theft, it's sharing. If the end user is too stupid to not hide their confidential documents when using Limewire then that, to me, is the same as if they'd left their car keys hanging out of the door of the vehicle: Stupid, and the insurance company won't cover it.