Consider the following scenarios:
Alice visits Bob's home and he has surveillance devices in operation for security which record all of their interactions.
Alice visits Bob's home after they go on a date and as a matter of general practice Bob surreptitiously starts a recorder as insurance in case she later attempts to accuse him of rape.
Alice visits Bob's home and they anticipate the interaction to be fraught. Bob doesn't know whether she might try to coerce or blackmail him, so he starts a recorder without her knowledge.
In each of these cases, has Bob done anything wrong?
Does it make a difference if he only refers to the recordings himself and does not publish or disclose them?
Does it make a difference if he only relies on them to prove Alice's lies or wrongdoing, thus retrospectively vindicating that Bob indeed had a reasonable excuse to be motivated to record her after all?
Does it make a difference that it is Bob's home?
How does the situation differ from a shop running CCTV on their own premises?
What if it was a phone conversation rather than in person at Bob's home?