Depending on how "user" is defined (and interpreted by the courts) it might be possible to avoid some of these regulations by splitting a service into two: the

Depending on how "user" is defined (and interpreted by the courts) it might be possible to avoid some of these regulations by splitting a service into two: the first would accept encrypted blobs from its users, and the second would allow its users to search for blobs based on a substring (i.e. a recipient header). Of course it would be easy to prove to the court that there was some sort of conspiracy going on, but it's not clear which service would be breaking which regulation, especially if there were "unofficial" third party apps for creating and decoding the blobs from and into plaintext, which the "official" apps didn't do.