Pedestrian Laws

I'm not sure what I find most interesting about this photo, taken on the corner of Old Georgetown Rd and MD-355 (Wisconsin Ave) in Bethesda, MD. Is it that someone felt it necessary to put up a sign saying that laws are enforced here? As if they couldn't enforce the law without a sign. Or maybe it is that I have never, ever, seen them actually enforce the pedestrian laws.

Come to think about it, I'm not even sure I know what the laws related to pedestrians are. I know jaywalking is technically illegal, but what about crossing the street in a crosswalk while the don't walk sign is on? Or, is starting to cross while the red hand thing is flashing a crime? "Pedestrian Laws Enforced" indeed.