National Defense Authorization Act Section 1021 contains the following
"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."
A "person" is inclusive of United States Citizens. "Belligerent Act" and "Associated forces" are both very vague terms.
This section also includes.
"Detention under the law of war without trial until
the end of the hostilities authorized by the Authorization for
Use of Military Force."
These combined allow the detention of American Citizens without trial by jury. This violates the sixth amendment.