Probably a fairly common occurrence unfortunately. I have seen this personally a few times over the last few years, once where someone from a great white was dumping their cassette in the grass at the side of a beach car park. Another time in a lay-by just south of Crianlarich, where the guy was emptying it down a roadside drain. If I had not had cars behind me would have stopped and told them what I thought about their actions.
Sometimes wonder if this is people who have hired a motorhome for a couple of weeks but have not bothered booking campsites so have to wild camp, with the result that they end up with full cassettes after a few days.
