We British as a nation seem to have a somewhat cavalier attitude to litter. People think nothing of dropping a sweet paper or other rubbish as they walk along the street, seemingly oblivious to the litter bin just a couple of yards further on. I once knew someone who had a policy that, whenever he saw someone do that, he would pick up the object and return it to the 'owner' with the polite comment, "Excuse me, I think you dropped this." These days, he would probably be assaulted and then arrested for disturbing the peace. So this is probably not a course of action I would follow myself, although I might be tempted on occasion.
The person or persons who decided to stop in the car park in our valley and clear out the rubbish from their car would be a prime candidate. Instead of using any of the THREE bins within a few yards of where they stopped, they decided to leave a pile of empty sandwich packages, half-drunk bottles of coke and other detritus right there on the car park. So much easier than actually getting out of the car and making the marathon trek to a bin, of course.
It does occur to me to wonder how they would feel if someone dumped a pile of rubbish in their front garden, but actually, they probably wouldn't even notice.