It's easy, you hide your crypto in innocent-looking communication.<p><a href="http://en.wikipedia.org/wiki/Steganography" rel="nofollow">http://en.wikipedia.org/wiki/Steganography</a><p>Will governments ban photo-sharing sites?  Probably not.  So your encrypted messages can still be distributed.<p>Also, banning cryptography will mean that online banking, VPN access, ssh, remote desktop, etc., etc. will no longer be possible.  So I doubt this will ever happen.