I would steer clear of plastic knives. While they might get you past the metal detector they could get you into a heap of trouble if you got caught with it on the inside.

The Honey Comb is interesting but do you really need a defensive stabbing weapon inside a courthouse? And what guy carries a round brush?

If you need a defensive weapon stick with the roll of quarters or something innocent.

For me, I'd make a pocket kit just for taking to court. Put it in a slim plastic case and don't put any metal in it. Glass, plastic, ceramic...you can't need that many things in a courthouse that you can't leave in your car.