the concept of a "public place" doesn't negate the harassment. the courts don't operate like computers, they demonstrate a lot of flexibility. most of the time, they use that flexibility to screw over poor people, but once in a while they use it to clarify the laws.

you can use some common sense to come up with the right decision.

legal: casually flying over a topless tanner and coincidentally getting footage of it.
harassment: swerving in and out of a topless tanner's personal space, trying to get a good shot.

it's not really a question of establishing the legality of drones, it's more a question of establishing a level of etiquette in using them.

http://www.youtube.com/watch?v=1WcukJ4Vs-4