Yes, show support for the 4th Amendment and at the same time - just in case the current level of support will continue to be ridiculed by the government - communicate safely:
I fail to see what this has to do with the protest or the 4th Amendment for that matter. Seems to me like you're treating the symptoms but not the cause.
Use RetroShare: http://retroshare.sourceforge.net/
It's:
1. Decentralized (real p2p, no central servers)
2. Encrypted communication
3. Easier to set up than encrypted email: Install -> Exchange "certificates" -> Done.
IMO, it's currently the best way to communicate.
EDIT: If you downvote, state what's wrong, because I don't see it.