I shall believe this story when I see good evidence that some burglar has actually used this system (and can explain its rationale) and that some householder has actually fallen a victim to it.
It was mostly used by tramps gypsies and other opportunists not always for the purposes of thieving but to denote say, a house with someone good for food, or money or maybe clothes, or that the dog was to be avoided.
It was taken up or revived by Irish travellers for their nefarious purposes.
It existall over europe, I suspect this recent crop is more likely summer visitors from Romania.
Instead of debating or denying the obvious on here why not contact the Utility sevices direct and ask them?
There are naive folk around that would still deny the obvious if they came home to a burgled house with, " come on boyo a mug lives here, new TV and mobile, cash money and credit cards all round kept in tin in kitchen" spray painted in bright pink aerosol on their door.
It occurs to me that it would be a very strangely altruistic burglar who helped other burglars who were 'stuck' for a property to break into.
You don't get it do you?
It's not the burglar doing the marking its his spotter. His mate might be round later, a day later or a week who knows.
Best defence is to erase these marks whenever you see them.
We had a spate of thefts, ride-on, quad bikes, horse tack etc from back gardens and sheds round here some few years back, the spotter was in one of those micro lights.