and do not let this post fool you. while i am sure you were able to see the stocks of the rifles (M-4's or MP-5's) up against their shoulders, i can almost guarantee the guns were not raised with the agents looking through the sights at protestors.
i have seen GWB's and Obama's motorcades and worked with secret service during their visits to my city. it's SOP.
it's both a show of force used as a deterrent and being at the ready in case an actual threat does arise.
You’re showing yourself to be making things up. It is NOT SOP. The Secret Service does not work on show of force. And YES, I’m a former federal agent and HAVE really worked with the FBI and Secret Service.