G's comment here reminded me that there are about a gazillion important civil liberty issues going on in the US right now.
Flag "desecration", restricted internet access, and violations of the most basic civil right at all - the right not to be hauled off and locked up without charges or access to counsel! - are all part of the creeping clampdown.
The ACLU is your best bet for one-stop shopping. While you're there, you can click on lots of easy action-alerts to send some outraged letters.