Hmm. I guess my thought is that if it became well-known that using Whatsapp, iMessage, etc. to communicate about illegal activities frequently led to arrest, th

Hmm. I guess my thought is that if it became well-known that using Whatsapp, iMessage, etc. to communicate about illegal activities frequently led to arrest, then knowledge of PGP and the like would spread because it's not too difficult to use. So then government would be able to read everyone's communications through those channels for no appreciable benefit. Obviously, that's total conjecture, though.