Moreover, Lincoln suspended Habeas Corpus. Madison signed the (later overturned) Alien and Sedition Acts. FDR interned American citizens of Japanese, Italian, and German ancestry, some of whom were second and even third generation citizens.

I have long wondered about the "privacy" of Internet communications, given that they travel through several "nodes" to reach a destination and could be intercepted at any of the nodes. In the military we were taught that message security was in the following order, most secure to least:

1. Written or oral message delivered in person.
2. Written message delivered by messenger.
3. Written message delivered by postal service.
4. TTY.
5. Telephone.
6. Radio.

"Written" included coded messages.

To that I would add the Internet to the telephone, or perhaps even lower.

Basically, if you don't want it known, deliver it in person. (This is one way that the Germans were able to surprise the Allies at the Battle of the Bulge -- the CG didn't trust even the Enigma machine and sent written orders by couriers. Of course, Allied complacency played a large role as well.)