Here is what artist KERI SMITH has to say about guerilla artists, in her book "The Guerilla Art Kit":
“The stereotype of the guerilla artist is someone who makes extremist work and who is constantly on the run from the law. I would like to expand the concept and define guerilla art as any anonymous work (including but not limited to graffiti, signage, performance, additions, and decoration) which is installed, performed, or attached in public spaces, with the distinct purpose of affecting the world in a creative or thought-provoking way.
A part of what makes public art so interesting is how it interacts with its immediate environment. Guerilla art can be used to beautify or recreate a space that is soulless or without character and bring it new life. Work that is impermanent reminds us that nothing in life is permanent – and teaches us to embrace change in our life, instead of working against it.
When others notice an art piece that is there one day and gone the next it creates a certain kind of energy within the community. It allows viewers to partake in the experience as a kind of detective, wanting to uncover the mystery.
Being a guerilla artist is secretive and exciting. There is a wonderful feeling of elation when you go out and place an anonymous gift in a public space, attach a painting to a park bench, leave a small painting behind in a public washroom.”
(From The Guerilla Art Kit by Keri Smith)