That's very much not safe! I was at a resort in Eastern Europe over Christmas and on the other side of a lake someone had a rig like that. It caused me no end of trouble because it kept sweeping across the place where I was seated and this was easily a 100 meters or more. Make sure you know what/who you are pointing at.

Please don't. It's so easy to blind somebody with a laser. I always get anxious near laser shows, especially when there's a change it's not done properly as it could still blind you several hundred meters away.