To expand on Horn Dogs post, this from Wikipedia.

Joe Wolverton noted that the 2013 NDAA does nothing to prevent the indefinite detention of Americans under the 2013 NDAA, but it only reiterates that habeas corpus is a right in courts established under Article III of the Constitution. "That such a right exists in the courts of the United States has never been the issue. The concern of millions of Americans from every band in the political spectrum is that Americans detained as “belligerents” under the terms of the NDAA will not be tried in Article III courts, but will be subject to military tribunals such as the one currently considering the case of the so-called “Gitmo Five

** The NDAA stands for National Defense Authorization Act