'My boss accidentally sent me a spreadsheet with everyone's salaries': Employee stunned to discover they're making $15k less than coworker with the same job

Did this boss do his employee a favor by sending them a spreadsheet with everyone's salaries, or is he pushing them out the door? That's the question this person now has to parse before they make their next move! 

Do you and your coworkers discuss your salaries together? I think many people know they're supposed to do that in order to make sure they're getting paid fairly. But the question can still feel so taboo that most people don't ask it. This person now knows everyone's salary at their company because shockingly, their boss literally sent them a spreadsheet with said salaries. 

This is an interesting case. How did the boss have access to that in the first place? Isn't HR usually in charge of that kind of thing? So to start, that's suspicious. Then, there's the intention behind such an act. This person is having to ask themself what their manager meant by providing them with this information. If I had to guess, I'd say that their boss realized that the new hire was making more than them, as well as the person who does the same job and makes more money, so the boss "accidentally" let them know about it. Maybe he's righting a wrong in the only way he knows how.