Your relationship to the person on whom you are spying matters. If that person is your child or your employee, you have a lot more leeway when it comes to monitoring their activities. If you think someone is spying on you illegally, file a report with local law enforcement so they can investigate your case.
Most cats snooze around 16 hours per day. The majority of their sleep time, however, is much shorter than the typical seven hours or so that humans average at. night. Cats tend to sleep lightly, without going into a deep sleep.
Kittens are usually considered to be adults when they're around 12 months in age. Although adult cats usually don't sleep as much as kittens, they too can boast pretty impressive shut-eye hours. Normal mature cats that are fit as a fiddle often sleep for between 13 and 18 hours daily.