Sidewalk Chalk?

More like Street Chalk.  It is warmer today and the neighbor kids are out in force.  There are also four little girls down the road from these two boys.  They have pretty much covered the street on most of our block with chalk drawings.  Looks like a  lot of fun, but cars are having to stop and wait for them to get out of the way.  Makes me feel like the crabby old neighbor lady, but I want to say, "What are their parents thinking?"