It’s Legal but it’s not really graffiti:

Techniques of fine art photography are being adapted by street art culture into what is being referred to as light graffiti. This technique is done with long exposure photos in which the artist draws with a light source and the lens of the camera captures the light’s path. It by no means is a new tactic in photography, but it is being adapted and becoming popular within the street art community.

The greatest thing about this is that it’s legal. You aren’t leaving any paint behind and there is not vandalism associated with this medium. I also like it because it is a creative and thoughtful approach to making something new. The other biggest difference is that you don’t need a wall to paint on. Light graffiti can take advantage of drawing in air and has allowed for interaction of other objects within the composition.

My biggest problem with light graffiti is that you aren’t leaving anything behind. The earliest forms of modern graffiti were all about “bombing” the city and putting your name everywhere for recognition. There is also something to be said about the illegality of it and the balls that it takes to do that. Don’t get me wrong, I’m not a fan of the people that go around writing their name on every sign they see, but I think the more muralist forms of graffiti can be some of the more profound forms of art that there are. They reach a large number of people and impact their opinions on the community around them. Real graffiti is about living within that community and it’s interaction with passers by. The only place where light graffiti can live is within a blog or someone’s portfolio. This is boring and has very little attitude. The real challenge, without leaving a $2,000 projector behind to be stolen in the street, is how light can be used in a more permanent way for me people to see and interact with.