Laser graffiti is harmless and fun. I think it would be a very effective tool to promote liberty. Just don't do it Boston or they may shut down the city. If anyone has info on how to obtain the hardware please post.
http://www.youtube.com/watch?v=EFWcAkxzkv4
Good lasers and a scanner that can do graphics like that on there own are expensive. Try around $2000 just to get a measly 60mw and the scanner.. and they are illegal over 5mw in the US. (thats anything bigger than a keychain) $2k just to get into the game. (you can trust me, I.. uhh.. know.. i mean knew a guy that owns.. err owned.. a 210mw.) you can get a 1-4w Skywriter for upwards of $20k.
If you want to actually be able to do the image itself with the laser.. well, bad idea.. because if your using a 1w laser to do this your going to have the swat team on your ass in no time. and they will probably charge you with assault as a laser that strong can cause people to go blind. (but it depends on a lot of stuff.. still the cops wont care about beam dispersement over distance.. and nm.. they just wont ok.) but they may not be able to tell where you are as the beam should be invisible so long as you are looking to the side of it.
This is not a laser making the image its a projector (5000 lumens, and that is rather weak.). It should be called light graffiti. They are using a laser to draw the image then a digital video camera sends the image to the projector of what was illuminated by the laser.. that's how I think they are doing it.
I don't know.. its a good idea, I'll get my lab team on this and see if I can't cook something up that's cheep and effective. There should be a way to do this without a laser so they can't send you to jail.
Anyone know if there are laws regarding projected messages?