Most often the religious traditions do not speak of the sacred abstractly; rather they name it--as Yahweh, Brahman, Atman, Allah, the Tao, Great Spirit, God. This is not to suppose that all these names mean the same thing. But it is to suppose that the impulse to name something sacred flows out of the experience of the sacred. (Marcus Borg, Meeting Jesus Again for the First Time, The Historical Jesus and the Heart of Contemporary Faith)

Legal walls are sanctioned art spaces. The owner tells the writer it's okay to paint them. For some writers, that's great because all they want to do is paint big images on exterior walls. Some of these artists don't care if anyone sees their work; they'll paint in tunnels, under highways, down alleys. For others, it's not okay because graffiti is not simply a style of public art but a deliberate transgression of social norms that is meant to be illegal and in your face. It's a political statement.

That statement is part of the conversation with and about property--whose it is, where it is, how it functions in our world, and who has the stronger voice because of that property. You might own that wall, but I'm talking to every commuter on the train with what I just put on that wall. They see you but they hear me. (more)

More on graffiti: Strange Attractions: Exploring Graffiti