On the other hand, you can use empty space in urban areas.
Rather than being damaged by irresponsible vandalists is better treated by street artists to work. For street artists in general with public facilities into own canvas. Working on the road is not always just to pass the art idea alone. Moreover, the works can also communicate with the general public.
Because his work is made in places where people and people are easy to see. The initial idea of making it is really to be used in the community. Often the work used to respond to the goods happens. It may be a work made to invite people to do something. There is also a means to reject something. Many people want to use or encourage government made propaganda.
Because it is the delivery of messages that are then sometimes governments that create works of art for a particular purpose. The reason is as the easiest messenger to the public. There is also a work to respond to government policies that are bad, poor society conditions, injustice and others.