Standing on the roof of a building on Tahrir Square, I had a perfect view down Mohammed Mahmoud Street. For months, most of the clashes with police happened on this street. In order to quell some of the violence, the police built a concrete barrier. In an overnight act of defiance, Egyptian artists came out and painted it. Now when you look at the burn marks on the street left behind from countless molotov cocktails, you get a smile.