Some guy writes down on a piece of paper (which is enchanted, I'm told), that....
That magic piece of paper has been around since Day 1. Executive orders by Presidents and Governors alike--and the written commands of all kinds of officials: arrest warrants, summonses, orders, subpoenas, writs, etc--have been routinely used to apprehend suspects, to seize assets, or to force the parties in a matter to appear.
This thread seems to revolve around a fear of losing a fundamental right guaranteed by the Constitution. Probably there is not an actual fear of arrest itself, since, with or without the bill, the police already are empowered to make arrests.
So the folks here are worried about the possibility that, if arrested, they will end up in military detention, and this "magic paper" will allow it to occur.
There is nothing to fear. The magic paper has no weight against a US citizen or resident, not because of what some other paper says, but because of the Constitution.
While it's true that Constitutional rights have eroded, especially in matters like wiretapping of citizens, the rights dealing with due process are the most fundamental, and they will be the last to fall. Remember you have a right to confront your accuser, and of effective assistance of counsel, and to post bond, and there is habeas corpus, the right to be heard if you claim you are unlawfully held. Also, the crime is referred to the court of jurisdiction. Acts of terror, weapons, or conspiracy, etc, already fall under federal jurisdiction, which means the charge is referred to the court of the federal district in which the alleged crime occurred.
So relax you're not going to Guantanamo, just Riker's island.