Street art has a way of putting on display the climate of any given city or country. By climate I mean, political climate, cultural climate, artistic climate and tolerance of civil disobedience. Art can be used in many ways and I have seen that often times, street art is one of the most powerful ways to express political discontent or promote cultural change.
If you want to achieve greatness stop asking for permission.
During my travels in Guatemala over the course of years it became very apparent the power of the graffiti artist. Some messages were raw and direct and others a more subtle but equally powerful paintings of a desire for justice in the face of rampant corruption. The most powerful indicator of the strength of street art is how quickly it need be painted over.