Some acts become morally wrong only due to the victim's knowledge of them. (For example, in an answer on Feb. 16, Charles Taliaferro says "internet stalking" is wrong because "the people you are studying so closely would not want this, should they ever know about it.") What is the moral status of such an act if the victim doesn't find out about it?
In case that sounds too obscure, here are two other examples (from real life):
1. Ogling: if a man looks at a woman and feels attracted to her (but does not say or do anything), and she finds him repulsive, she would feel that she had been wronged if she knew about his attraction, but has no way to know about it.
2. Jewish law requires a group of 10 Jews to worship (defined as people whose mothers were Jewish). I know a non-Jew (Jewish father only) who tricked a group of 9 orthodox Jews by claiming to be Jewish and praying with them. If they knew he wasn't Jewish by their standards, they would have been harmed, but they had no way to find out.
In the ogling case, one commits a wrong merely by thinking, but the Judaism case is a matter of outward behavior. In all cases, it is the victims' knowledge of the crime that causes the harm. One might be tempted to say these acts are wrong because the victim might find out, but it's easy to construct situations where this couldn't happen--say, the victims are strangers whom the perpetrator will never meet again. I'm very curious what philosophers have to say about this.