You can't just walk around downtown firing high powered lasers up between the skyscrapers, that's for sure.
As soon as someone says the laser is harassing them, it becomes a potential crime.
Best advice I can give is to use your non-FDA compliant high powered lasers in lightly populated areas.
People just love to call the cops. "Hey, there's a guy shining a really bright laser around over there".
The police will let you know whether it's a crime or not.
Some will be cool with it and some will not be and next thing you know, the police will own your laser.