like i said above, cats typically tend to "walk on walls, fences, enter other's homes etc" ... the cat strapped with a watch-sized device could be used to monitor/record (not necessary this proj).
cameras and microphones are very cheap these days.
of course if one's not bothered about privacy, then the issue doesn't exist (magic)
I mean, it doesn't impact my privacy if a GPS-tracked van drives past my home.