Weigel vs Breitbart, Ctd

Were Weigel's emails leaked or hacked? Dave emails to clarify:

Just so you know, I am not disputing anything about JList with anyone in my interview with David Carr. He quoted me accurately, but what I was saying was that people shouldn't immediately turn this into some bloodless "media, what to make of it?" story. Someone, probably someone on the list, spent a lot of time digging into old off-the-record emails and unleashed a bunch of them to hurt my career. I called this "hacking," because that was the word that came to mind for someone digging around online, but I am not saying "a hacker" went after me. I don't know who did; I assume it was a member of the List, but who knows?