Street art has a power within communities, like ancient cave paintings. We don't know who the artist is but their message, their story, their images are present. There are artists who are known by name, but not by identity (Banksy, Space Invader) and through their hidden identity a myth is created and the artist becomes a hero in the public's eye.
The true meaning of street art is derived from the anonymity of the artist, and the myth created around the artwork and the artist.
The anonymity of the artist creates a myth and a hero that the public responds to, and escalates the popularity of street art.