And yes, I checked--it wasn't an enormous gas-guzzling SUV hybrid. Not that I think hybrids should be allowed in spots reserved for alternative fuel vehicles anyway, since they don't actually use any alternative fuel. In fact, I don't really think having alternative-fuel-only parking spots makes any sense in the first place, since it implies that vehicles which run on ethanol are actually environmentally friendly, and not a giant hoax made up to benefit big agribusiness.
I guess it is possible that the driver of that SUV could have given me a well-reasoned explanation of how he parked in that spot to make a statement about the problems inherent in using "alternative fuel" as a proxy for "environmentally friendly," but I suspect that he was more interested in being a douche bag. Unless that SUV has been modded to run on home-brewed biodiesel.