in the Snowden leaks, there is a document that lists the opinions of NSA's legal counsel about a list of collection practices.

one of the questions is whether passwords sent across the network are considered metadata or content.

NSA legal says passwords are metadata. which means NSA can scan all traffic for passwords and steal them and no FISA warrant is needed, nor a subpoena.

of course NSA already has a dozen programs just for extracting passwords from UPSTREAM passive collection. and presumably this means everyone in the FVEYS gets access to everyone's passwords, since they pool their capabilities and collection.

whatever the Courts rule about local cops and passwords, it doesnt apply at the level of SIGINT collection, which enjoys its own separate and secret system of laws.