That kind of inconsiderate behaviour drives me nuts!
Like DavidB, I park as far as I can from other cars in supermaket carparks, but as sure as eggs are eggs, I'll return to find another car (usually something like a rusty 20 year old Escort on it's last legs) parked inches away from the drivers side of mine!
I'm certain there are a few idiots who do it 'for a laugh'!
I was once parked in a carpark, way out on my own and returned to find an old Sierra parked so close to mine, that I had to clamber in from the passenger side!
I have to park in a private carpark at home; on the whole, most of the neighbours are pretty good, but there's one who's car I will go out of my way to keep away from!
And woe betide anyone who find themselves parked next to her daughter when she's home from university; you are guaranteed a sizeable ding when she uses your car as a door stop... even after one of the other neighbours had a 'quiet word' with her regarding her 'carelessness'.
Mind you, you've only got to look at the state of her Clio to realise that she's not a 'car person'.
Not a straight panel on it, including the plastic front wings!