What I see in this selection of street art is a willingness on the part of the writers/artists to challenge prevailing values. The slogan "Skepticism Now" encapsulates that outlook. That slogan, in addition to conveying a powerful message in two words, ommunicates without ideological dogmatism. There is humor here offered sagaciously at a one-to-one level.
Humor is common to all the caricatures and graffiti selected for this book and that makes this selection of political street art unique. I believe that the humor humanizes what people frequently experience as alienation from impersonal and uncaring governmental and economic systems and the vapid value prioritization that is enmeshed with those systems. Humor narrows the power gap.