If you would like to get involved, http://www.restorethefourth.net/ is the starting point.
Reasons I, personally, am joining this movement:
Guantanamo (though undoubtedly many dangerous people are there, it is a clear violation of human rights to hold people without trial, and not all held are guilty)
Extraordinary Rendition (the habit of sending people to politically allied states for the purpose of torture, since we "don't do that" here)
No-fly lists (not subject to review, based on low evidence, with many false-positive examples)