I had an occasion this morning before work to visit the San Mateo County (Southern) traffic court administration building.
This is where you go if you get a ticket in San Mateo county to pay the bail, turn in paperwork, what not. This is not the courthouse. This is the place where there's a velvet-rope line leading to a bunch of bank-teller-like windows with pasty faced bureaucrats that work computers. There are, oh, I don't know, 5 windows, and the building inside is maybe 10'x20'. Relatively small. I've never seen a DMV that wasn't huge by comparison.
They had a metal detector and an X-ray machine. I had to take off my belt to go hand my paperwork to the aforementioned pasty-faced bureaucrat.
Let's say I decided that my speeding ticket was the last straw and I was going to take the bastards out. If I walked in the front door with an uzi I could hose down the whole room from right there. Hell, the metal detector makes a good aiming point, actually.
In other words, the purpose of security screening is that it takes place far enough away from the thing you're trying to protect that if any funny business goes on, it has no impact on the sensitive stuff.
And what sensitive stuff? This is not the courthouse. Even if it were the courthouse, there aren't any real judges at traffic court, just administrators. Why are they wasting everybody's time (and the taxpayers' money) protecting this stupid little shack of clerks like it was a fucking airport?