Clarkson mentioned this in his column yesterday, was in a park in London enjoying the sunny weather and foreigners were just throwing garbage everywhere, they have a different attitude to litter (except the Japanese, they're neater than we are) and although I sound like my granddad the younger generation seem to chuck litter about as well instead of using bins.
Most annoying to me is people throwing rubbish out of their car windows when they can easily take it home or wherever they're going and bin it.