I love chalk art. I have worked in this medium for years- sometimes going to the beach after midnight to create covert chalk murals for the people. I also lived for years on a busy street, with a big blank wall between my home and the traffic- this wall was my canvas. The police would occasionally come by, but then leave me alone when they found out I lived there and it was only chalk. (I eventually wrote "It's only chalk" so that people who drove by would not be afraid or offended) My neighbors would leave chalk on my doorstep, so I knew they approved.
I try to never write political or religious statements, only positive, colorful statements to keep with my idea of "FUNism". I often steal slogans, but I think I read a quote by Pablo Picasso that said "immature artists borrow, mature artists steal" so- that's my excuse. The art is mine, the words aren't always, and I hope if I wasn't able to "steal" the words, that I at least made them worthy of being borrowed.