I just ran across this one and I haven't explored it, but it looks good for this thread...
U.S. CONCENTRATION CAMPS
FEMA AND THE REX 84 PROGRAM
http://www.abovetopsecret.com/pages/camps.html
There over 600 prison camps in the United States, all fully operational and ready to receive prisoners. They are all staffed and even surrounded by full-time guards, but they are all empty. These camps are to be operated by FEMA (Federal Emergency Management Agency) should Martial Law need to be implemented in the United States.