Also of note is that a 150 milliwatt green laser (15% of a watt) will shine for miles through the atmosphere.
Putting your finger under a laser is apples and oranges to what we're talking about. The point is that the energy of the laser WILL dissipate over great distances. I would be glad to put my finger under a 50 watt laser that is 5 miles away from me and passing through the atmosphere.