(via Reddit) I'm pretty far left, and I'm a philosophy major. That combination tends to leave me leaning closer to conspiracy theories than I'm comfortable with. One of the ones that makes me feel a bit funny is the National Defense Authorization Act. Specifically, Section 1021(b)(2).
SEC. 1021. AFFIRMATION OF AUTHORITY OF THE ARMED FORCES OF THE UNITED STATES TO DETAIN COVERED PERSONS PURSUANT TO THE AUTHORIZATION FOR USE OF MILITARY FORCE.
(a) IN GENERAL.—Congress affirms that the authority of the President to use all necessary and appropriate force pursuant to the Authorization for Use of Military Force (Public Law 107–40; 50 U.S.C. 1541 note) includes the authority for the Armed Forces of the United States to detain covered persons (as defined in subsection (b)) pending disposition under the law of war.
(b) COVERED PERSONS.—A covered person under this section is any person as follows:
(1) A person who planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored those responsible for those attacks.
(2) A person who was a part of or substantially supported al-Qaeda, the Taliban, or associated forces that are engaged in hostilities against the United States or its coalition partners, including any person who has committed a belligerent act or has directly supported such hostilities in aid of such enemy forces.
Bold emphasis mine.
When Obama signed the bill into law (noting that presidents don't get a line-item veto) he issued a statement stating that his administration would never interpret the law to mean that they could detain American citizens without trial. But his administration has stated their intent to fight the New York ruling that the section was unconstitutional.
I don't tend to believe the type of people who believe, for example, that FEMA has prison camps hidden throughout the US. But the government does sometimes do horrible, horrible things. Tuskegee, for example, or Guantanamo Bay.
I don't know how to find that line -- how to figure out which crazy-sounding claims are true and which ones are, you know, crazy. I like to think I'm getting better at it (In high school, I briefly thought that 9/11 was an inside job) but it's still not easy.
I don't know of any American citizens being held without trial (apart from Bradley Manning), but I wouldn't, would I?