If he didn't do anything then people would be blaming him if something had happened. Its a damn if you do . . . damn if you don't situation.
In the D.C. area they increase security all the time and it isn't reported on the news why or that they have increased security. I know when I get to the Pentagon Train Station and I see the Military Hummers, MPs, dogs, Pentagon Police and Transit Police, that they received a threat. Its becoming the norm here.