Anything can be called graffiti if it's out in the open for others to see. Technically it's supposed to be on a wall, but we don't need to get all technical about a post on a blog.
I think that is from a an experimental art group called the Graffiti Research Lab (GRL). They use home grown engineering to make new graffiti technologies that people can rig up at home, and I think the picture is actually from their new experiment that involves lasers, rather than just flashlights. They are pretty cool, I suggest checking them out.
In the 30's, he worked with professor Edgerton from MIT.
Pablo Picasso himself tried to do this : http://www.zeblog2latribu.com/index.php?2007/02/20/281-peindre-avec-la-lumiere
here's lichtfaktor's new stop motion filmed in london (where they 'graffiti'd Big ben!)
http://video.google.co.uk/videoplay?docid=-8109178600655663537&q=lichtfaktor&total=6&start=0&num=10&so=0&type=search&plindex=4