I believe the goal of this and similar mistreatment is to emphasize that lowly employers of the Congress are not to set foot in public buildings unarmed, not bent on destroying the building, just in protest.
Consider those who invaded and damaged Federal Buildings in so many cities across America, with weapons in hand, with Molotov cocktails and other tools to deface and destroy the building, in the professed attempt to actually harm people, served little if any time for their crimes.
One of these models seems to work out better for those going in the building than the other.