Shouldn't be there, or shouldn't be parked there?
What does the law say?
Obviously you could drive through one - is stopping long enough to open the door and let someone out much worse than driving directly through (something like 10 seconds vs. 45 seconds)? It seems to me like the place to draw the line is at the word "parked." As defined above you are only "parked" when you aren't loading or unloading (which is what we are discussing -mostly-in this thread).
I don't know what the law is on this. I'm mostly just curious. For the record, I don't park in handicapped spots at all.