From my time living in Europe, I can recall square metres (or yards, depending on location) of walls and other flat surfaces being defaced with graffiti. Defaced, because however artistic the graffiti, the flat surface and the surrounding area were not improved by having “SPUDZ RULES OK” in multi-coloured letters sprayed across it.
The Thai approach to graffiti is more genteel. I have yet to see graffiti sprayed in places where it might be considered an eyesore. But offer an existing eyesore in the form of a partially demolished building, and the lads with spray cans will be there in a flash.
Sadly, this is not an indication that the youth of Thailand are little angels. They are too busy taking drugs, riding round on motorcycles at high speed and shooting each other with illegal guns to have any time left for spray-painting buildings.