You are kinder than I would have been. After calmly explaining it once and requesting that they relocate their trash then getting their weak bull s**t response I would have ID’d myself by my retired military rank and given then a direct order to relocate their crap. Know that they would just laugh at me I would have contacted capital security to come and make them to relocate their sh**.
I have many veterans in my family...would be hard-pressed to find one that wasn't...immediate family resting at Arlington. If I had been there; I would probably be in jail.