There are many reports (and videos) of hundreds of fully operational "concentration camps" in America (you can search google or youtube to see some of them). While these camps are currently said to be empty (except for the staff and security at the bases) one wonders why America would need these (said to house on average 20,000 people each).
One theory circulating on the Internet is that they could be used as a place to put those who do conform if martial law is declared in America. While this may sound extreme, Bush Jr has already legislation into place for a president of the USA to be able to declare martial law, under certain circumstances. If martial law is declared the constitution and rights currently held by people would be suspended (such as a right to a trial). Peoples property could be taken, they could be relocated, or detained (without trial), and the military could be utilised by the president to maintain the government and its decisions within America. For example, if martial law is declared, military forces could be called upon to deal with domestic (American) situations if the domestic agencies (eg police) fail, or refuse, to carry out the orders of the government. It is important to note, that this legislation could be used on Americans and Non-Americans alike if they are in the USA.
Website links to:-
Article on American Concentration Camps
Video on American Concentration Camps
Article on martial law in the USA
Law changes in America and how Americans are at risk of losing their constitutional rights.
Full Copy of the legislation: National Defense Authorization Act (NDAA) from 2007 (see section 1076)