[Blood of Tyrants]

E-mail monitoring is next to useless. The real bad guys will simply use encrypting.

[elfman2]

"The real bad guys will simply use encrypting. "

I suspect that's exactly what the NSA looks for in the billions of messages sent every hour. Encryption tags probably cause the message to be directed to queues for brute force decryption and examination. If you're a bad guy, encryption is probably the worst thing you can do.