Unless they have an intelligence sharing agreement with a nation that happens to pick up signals from americans, from who they can request that data. And maybe

Unless they have an intelligence sharing agreement with a nation that happens to pick up signals from americans, from who they can request that data. And maybe there exists a network to share the raw data, wouldn't that be convenient? Or you could have a secret court system (FISA) to bypass most of the protections normally granted by due process?