It all started in one of the woodlands around here. Dog poo that grotty people hadn't picked up, suddenly started being covered in what looked like blue spray paint in a perfect square over and around it. Obviously I thought it was very odd.
Then the local nature reserve started having yellow circles over dog poo left behind. This yellow stains grass areas but doesn't seem to stay on tarmac. So by this point I'm even more wtf 

Then on another walk there has now started to be what looks like talcum powder thrown on dog poos left behind.
So does anybody know what on earth this stuff is and why it's being put on? 