Some people will simply refuse to let all and sundry (we have no idea as to who reads and acts on intercepted emails) to read private emails and they will there

Some people will simply refuse to let all and sundry (we have no idea as to who reads and acts on intercepted emails) to read private emails and they will therefore turn to steganography or one time pads with a seemingly ambiguous pre-arranged code. Good luck with reading the latter or even thinking it has a hidden message.