The old multi-colored terror alert system is being scrapped and replaced with just two levels: elevated and imminent. Why the lowest level will be known solely by a word whose only meaning is that it's not the lowest level is completely beyond me.
Terror alerts may be broadcast on Twitter and Facebook only "when appropriate", according to the hitherto top-secret document. Terror threats are made public only when members of Congress, various counter-terrorism officials, governors and mayors have been informed. The document even specifies how many minutes US officials can wait before organising urgent conference calls to discuss pending threats.
So as long as no threat to national security ever requires a description over 140 characters, we should be COMPLETELY PREPARED.