Your paint comparison is plainly erroneous. Paint poses practical safety and environmental problems and is therefore not comparable to chalk. The rest of your

Your paint comparison is plainly erroneous. Paint poses practical safety and environmental problems and is therefore not comparable to chalk. The rest of your comment appears based on an equally faulty premise -- that I would think the messages need to be washed away (naturally or otherwise) at all. Why on earth would I invite massive use of chalk on sidewalks for virtually any purpose if I would be bothered by its presence? In my view, it was BoA's choice to waste their money on an overpriced erasure of a message they dislike. My opinion on the use of chalk on sidewalks changes not one whit whether they make that choice or not. Chalk messages could remain on sidewalks until universal thermodynamic equilibrium is achieved, I really couldn't care less.