NDAA is the National Defense Authorization Act (of 2012)
It was signed by Obama December 31, 2011.
It, disputably, gives statutory authorization to the President to designate a person as an enemy combatant subject to indefinite detention without charge or trial.
There is contention over whether US citizens are subject to these provisions.
I took no comfort from Obama’s statement while signing that he would not use it for citizens, which only implies that the Act does authorize such.
The Act is ambiguously worded.