I was at the White House about 2 weeks ago, the morning GWB was boarding Marine 1 on the way to his physical and vacation. After bicycle cops cleared the sidewalk near the south lawn, a bunch of ninja suited SS guys climbed up on the berms behind the fence to keep an eye on the crowd while Marine 1 landed and picked up GWB. The SS guy nearest me was carrying his MP-5 with his hand on the pistol grip, under a large nylon flap that kept it mostly hidden. He also had 2 heavily loaded duffel bags about 36" long, 16" wide and 14" deep slung over his right shoulder (he was right handed).
After Marine 1 left with GWB, and the SS guys relaxed a bit, I asked him what was in the bag. He looked me over (I noticed him check out the Team AR-15.com logo on my shirt [;)]), smiled a little, shook his head, and walked away.
Since he carried plenty of spare mags on his vest, I'm guessing there was probably some kind of light anti-armor or maybe even anti-aircraft weapons in the bags. Anybody have a better guess?