Just because something is inherently evil (evil isn't the best word for use in utilitarian arguments, Jeremy Bentham uses pleasure & pain) doesn't mean you should never do it. If you take hurt as being inherently bad, you could argue that it is ok to do some bad to prevent other bad or cause good (Bentham again).

Besides that, I agree with you on everything else. If we are going to call invasion of privacy evil "just because," we should define it pretty soundly. If we try to define it, I think we find that it's mostly about expectations, so making some clear rules/agreements is important.

Se my comment upthread from here.