I don't think this picture shows fly-tipping as such, but more the result of over-flowing and unemptied bins. Still very nasty for children (anyone) to have to negotiate, but we're not talking mattresses or tyres or building waste here, I'd think. Which we have had locally at times.
They are certainly persistent - they try to sell us it every time we walk up and down Lordship Lane - no matter if you told them no thank you three minutes earlier! Anyone else feel that sense of relief when you walk and see they have someone they are talking (invariably looking like they are trying to get away) allowing you to walk past without becoming their next sale target?