Just some thoughts then, to try to answer that question.
Even though the information itself might have not been anything they had any real need to hide, your act of snooping is invasive in itself. They trusted you to behave responsibly and you failed, it's as simple as that.
You personally seem to think that such an invasion of privacy is something bad. This means that you would (by your own standards) hurt someone just to prove a point. I'd say this is not a quality i generally admire in people (And I might very well tell that to someone doing so)
Remember that it is never the victims fault, it is the perpetrator who performs the act. Their failure to defend against privacy intrusions does not justify your behavior anymore than my failure to take self-defense classes justifies someone assaulting me. Just because he follows up the beating by handing me a leaflet to the local gym doesn't really make it ok.
