Busking, I mean REAL busking ie; having a real entertaining talent and sharing it with everyone that passes for potentially no reward, has to be the most submissive, passive and most honest form of exchange known to man and is morally heaps ahead of an apparently legitimate, bone-fide door to door direct salesman (whatever he's selling) or indeed the miserable passer by who clearly likes the music but doesn't offer anything in appreciation (who's legal right and freedom it is, of course, to do so at will).