The funniest thing about Prius drivers, at least in the NYC/LI area? They like to blast their way down the highways and byways in their little battery boxes, thereby making their vehicles run less efficiently than a non-hybrid version would have run. No kidding; while there isn't a non-hybrid Prius to do a direct comparison with, there are both hybrid and non-hybrid versions of the Honda Civic and when the hybrid version is run at full speed (or higher) on the highway for extended periods of time (e.g., for more than one or two exits), the hybrid ends up performing worse than the non-hybrid, including in terms of fuel mileage.
In other words, those sanctimonious sluts are more often than not doing more harm, rather than less, than they would be doing if they had simply driven a nice little non-hybrid subcompact.