It's almost baffling to think about today, because we use cryptography so widely from online purchases to email logins, but it used to be considered a munition, and Zimmerman was investigated for "arms export trafficking". The use of cryptography was not always a given. He and his dedicated lawyers won that war for us. It wasn't even that long ago, less than 20 years, and we take it for granted that sending encrypted messages is not a crime. Let's remember Zimmerman for that heroic fight, and of course, for inventing this Pretty Good Privacy scheme.