I can think of some stuff, that while perfectly legal... would have .gov
really pissed at the folks doing it... if they actually were engaged in wholesale domestic spying/monitoring.
Something akin to a combination of TOR, peer to peer technologies, and massively parallel distributed computing like SETI@home/folding@home on the BIONIC model that does nothing but generate MASSIVE amounts of noise to signal ratio into which whatever files or messages you want to actually send are inserted...