It turns out that existing technology goes a long way toward solving this problem. Ellen is home most of the time, and she can see everything that goes on in our house. She knows when Jackie is home, she sees who knocks on the door, and so forth. Ellen is endowed with tremendous curiosity and a propensity to talk. As a result, Jackie could not get away with anything at home.
Friendly surveillance is a good thing.
Certainly, it is less expensive and dehumanizing than hostile surveillance. The Internet greatly complicates the problem of surveillance. Even Ellen would have a difficult time detecting when Jackie engages in cybersex. We should be careful about how absolutist we become concerning privacy. We may be able to preserve the right to privacy with respect to strangers, corporations, and government entities.