Re: In that case...
Aside from putting up signage I think that motion triggering from an area on my property is enough to limit the recording to a suitably small set.
But I'm keeping the audio on, since one of the main reasons for the camera is an instance of someone following me home and then coming back later with "help" to assault me, the audio recording there would be important.
I'm sure it used to be the case that there was no expectation of privacy whilst walking down the street.