I believe that graffiti is vandalism. This is because people build offices of housing and they want it fully clean and sparkling not dirty. I understand the artist doing it on walls, but not on building. Most graffiti is permanent so you can’t remove it and some may not like it. Others like it but not everyone does. If your going to do it on walls, ask first as well. The owner may or may not be happy with you doing this because they are not always going to say yes.