1. Martial law is rule of the civilian population by military apparatus, under a military or civilian government. Civil rights may be suspended, but that is not always the case.
The word "Martial" is base on the name of the of Roman god of war, Mars.
2. The legislation is toxic. Obama is wrong to take this power.
Section 1031, part b, (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"
Even criticism of a coalition partner makes you a potential victim of this act.
Section 1031, part c, (1) "Detention under the law of war without trial until the end of the hostilities authorized by the Authorization for Use of Military Force."
You can be held indefinitely without trial.
During the campaign Obama promised to release the Gitmo POWs, and hasn't, we can't rely on him keeping his word about his ideas of prisoner rights. The act gives him the power to arrest and imprison American citizens without charge. His views on civilian rights don't seem to include freedom. We may have a problem.
No government should ever be this powerful.
Text of the NDAA - http://www.gpo.gov/fdsys/pkg/BILLS-112s1867es/pdf/BILLS-112s1867es.pdf