They (NSA, GCHQ) stole many SIM card authentication keys, so they can probably eavesdrop on UMTS conversations with them: http://electrospaces.blogspot.com/2015

They (NSA, GCHQ) stole many SIM card authentication keys, so they can probably eavesdrop on UMTS conversations with them: http://electrospaces.blogspot.com/2015/02/nsa-and-gchq-stealing-sim-card-keys-few.html http://electrospaces.blogspot.com/2015/02/nsa-and-gchq-steal...