But IIUC US Federal law generally ignores intent -- in a bad way for the accused. A lack of bad intent isn't a mitigating factor.
Prosecutorial discretion is tricky enough to begin with. But also mix in disregarding intent, and season with charging people multiple times for the same act? Federal prosecutors can be little Putins.
He would be liable for exposing private data, because of the kind of data he found wouldn't be reasonably published.