The program is structured as a privately owned business based in the city government.
It uses soluble abrasives[1] (baking soda combined with high pressure water)[2] and paints matching the city's official color scheme to erase all varieties of graffiti.
Mayor Richard M. Daley started the initiative in 1993.
In May 2009, on the instructions of Alderman Jim Balcer, Graffiti Blasters painted over a commissioned mural by artist Gabriel Villa on private property without the permission of the artist or property owner.
A spokesman with the ACLU of Illinois said Balcer acted illegally, saying "He was elected to be an alderman.