When you use the PIN to your bank account you expect both the bank and ATM technicians and programmers to respect your secret. There are laws that either force them not to remember the PIN or impose punishment for misusing their position of trust. I don't see how such situations or cases of blackmail would be resolved without assuming one person's right to have their secrets not made public by others.

I'm not just nitpicking. I would love to see a watertight argument against communication perversions. Have you written anything on the topic?