Do not shoot lasers at people.The very bottom of the laser projection should at least 3 meters above the floor, so there is clearance between someone’s head and the lasers. Laterally, there should be 2.5 meter distance.
As with all lasers, never allow any laser beam to enter the sky. Laser beams striking aircraft can blind pilots and is considered a felony offense in most countries.
We highly do not recommend scanning the crowd unless there is explicit permission granted from your government. Check your local laws first before using a laser in public areas/outdoors.