Who is in the wrong here?

You shouldn't expect that anyone is looking through your personal belongings, especially at work. This is a pretty big violation of privacy, no matter who you are. And while it shouldn't be taboo to talk about salary, we shouldn't be snooping around in others' stuff just to find out. That's for them to disclose if they'd like to, not for you to sniff out through some subterfuge. That's what happened here, though, and it had a pretty profoundly negative impact on the worker in question. Nobody wants to feel like they're not respected in their place of work, no matter who they are and what they do. We want to feel like our peers think highly of us and want us to be there. At the very least, if these feelings aren't genuine, we want people to put aside their feelings and treat us professionally no matter who we are. We all deserve that, whether or not we get it. The man in this story was made to feel like his coworkers didn't want him there and didn't value his contributions. All because they found out how much money he made.