It's even illegal to stare in my front window from the sidewalk, or with binoculars, even if my curtains are open.
I've always wondered what the guidelines are for something like this in various jurisdictions. I live in Phoenix, and for about a year I lived in an apartment complex with some very large and revealing sliding glass doors that all face an interior common area (swimming pool, etc.) — naturally, most residents kept their curtains closed most of the time for privacy. There was one guy, however, who kept his curtains wide open seemingly 24/7, and he always had a bunch of crazy crap on the walls so that you couldn't help but feel your gaze drawn to glance that way while you were going about your business.
The common area was a semi-public area; residents had keys for when the common area was locked, but guests didn't need special permission to be there.
So one day this guy walks out of his apartment onto his patio wearing nothing but a bathrobe and holding an alcoholic beverage in his hand, demanding to know why I'm looking into his apartment (as I had apparently done so multiple times while going to/from my own apartment). Then he demanded, in a slurred and drunken manner, that I not look into his apartment. Putting aside the issue of whether or not my neighbor was in fact guilty of public intoxication, I still don't know if he had a legal leg to stand on. Had I pressed the issue, would a judge have considered his request reasonable? (Demanding that people not look through an unobscured window that is larger than the dimensions of most human beings and is at ground level where pedestrians are likely to travel doesn't seem to be very reasonable or practical, but the law doesn't necessarily have to be written in a reasonable manner.)
Note that I didn't "pause" to watch for an extended period of time, nor did I have binoculars, nor did I have anything like a camera. (Camera phones weren't even a thing at this point in time.) The point being, if someone has a very expansive view of their own privacy rights, they will not be deterred even if the law is not on their side. This is also why photographers are being accosted by security guards more and more frequently under the guise of "no photography" policies in public places (e.g., Grand Central Terminal) where no such policies actually exist. I shudder to think what some Phoenix residents are going to do if this ordinance passes since quadcopters are popular items sold in the Phoenix Metro area.