Just to add that the various Surveillance Devices Acts in the states can prohibit observation of “private activity” without the observed party’s consent.
But “private activity” is not:
- an activity carried on “outside a building”; or
- an activity carried on in any circumstances in which the parties to it “ought reasonably to expect” that it may be observed by someone else.
So activity on a balcony or on common property areas that can be easily observed by others, is not “private activity”.