It further means that it no longer matters whether they have actually carried out any terrorist acts; all that is required is that they are terrorists. In practice it means that they only need to be terrorist suspects.
...To repeat the point, in law enforcement you can’t kill suspects, and under the laws of war you can’t intentionally kill civilians. Under the new rules of the war on terror, you can kill civilians by labeling them suspected terrorists.
Terror, Legality and the New Rules of War