I see people do that crap all the time. Two weeks ago, I went to a 7-Eleven with my nephews to get some late-night munchies, and of course the only handicap spot available was taken (I use a wheelchair). I noticed that the vehicle did not have any placards, and noticed a young lady sitting in the passenger seat. I approached her and asked, "you don't have a handicap placard do you?" to which she replied a simple "nope."
I didn't want to make a big deal or anything, as I'm actually pretty used to this sort of shit happening, so I ignored her and moved on. My nephews were just ahead of me opening the door, when some guy walked out and heading towards the car in the handicap spot. I figured he was the driver, so I turned around and asked him, "that's your car, isn't it?" He nodded, so I replied, "that's pretty messed up man, I needed that spot for my van" (my van has an automatic pullout side-ramp). He shrugged and kept walking, and out of nowhere he said "punk-ass bitch ni**a."
I'm Mexican, and he was black. It totally caught me by surprise. It's not like I expected an apology or anything, but it was pretty crazy that he was insulting me after he committed the fault, so I immediately replied with "fuck you say?" He turned around and noticed how pissed both of my nephews looked. They're 16 and 17, with athletic-type bodies, both around 6'2" or so. He was 5'7" at most, fat and out of shape. He ran and jumped in his car, while both were yelling obscenities at him while telling him to get out. He jolted out of the parking lot and disappeared in a heartbeat.
I called the police immediately to report the incident, but they basically told me they cannot do anything unless they are present when the crime is being committed (i.e. committing the traffic violation), even though I had multiple witnesses and a picture of the license plate. It's not hard to see why people take over handicap spots without any fear of retribution or consequences. Sure wish they would take away people's driving license, or something more severe than a useless $250 ticket.
Anyway, sorry for my lame-ass story.