Seized a box of ammunition? Why? Was it illegal to possess? We better start closing every Wal-Mart in America then.
Comes back to the War on Drugs, which is as silly today as prohibition was then. If anything, I'm willing to bet the house they raided was, at best, a low-level stash. But it was cool to get dressed in war paint, break out all the toys, and just generally play swaggering tough guy. (I'm probably getting a little carried away...)
What, actually, did they accomplish? Arresting a guy for taking photos of public servants doing their work? On the pretext that he was “obstructing” the raid? How can he possibly be obstructing?
He dissed their tacticoolness.