I can definitely agree that this is in fact, not so funny to the victims and I do not condone or support Vandalism (And the times I have supported property destruction, I feel it is your obligation to make it obvious exactly who did it, preferable with the owner of said property watching as you do so blatantly. It sends a better message. Property damage without a message or identity is meaningless, mindless) because I know what that is like.
In the same breath, I will admit that it is a bit funny, but as previous posters have mentioned, this is hardly new. This has been going on since the SMART came about and well before, with other, equally puny vehicles.
As for it being a prank, it is certainly not, as it results in damage to someone's car (a rather expensive car, actually, speaking comparatively) and honestly, since many people take their cars seriously or may actually need them for an emergency or to get to work, school or anyplace else the next day, this goes from funny to aggravating instantly, if you are on the receiving end.
My friends and I prefer much more harmless pranks to one another. These tend to either involve swapping our intended victim's cars with our own (as we tend to have copies of/access to one another's keys) or to finding ways to put other cars into one another's garages, while the victim is out, so we return to some obtrusive vehicle taking up space in our garage. Usually, we use those new Camaros, since it seems that everyone I know has a mutual disdain for them.