IANAL but it doesn't sound like he did anything criminal to me. He's obviously misguided and silly, thinking he can draw statistical relevance from assumptions based on his personal reading of Facebook profiles, but there is nothing illegal about reading information that someone posts on the internet.

Cyberstalking, to the best of my non-lawyer knowledge, involves real, disruptive harassment, not just a guy who saw you were friends with some other guy and drew some wild conclusions from that.

Barr never dropped the names so any post-facto prosecution for cyberstalking that would have been primarily based on his use of electronic methods to "identify" Anonymous leaders is unlikely.

I don't think there's anything wrong with doing your own detective work, and you certainly don't need a warrant to follow Facebook or Twitter pages. Private investigators do this kind of stuff in the "real world" all the time (granted, they have licenses).

I agree that Barr is incompetent and/or a tinge off his rocker, but the idea that only law enforcement should be able to search publicly accessible data is silly. If I find the page of a guy I haven't seen in five years, should it be illegal if I spend some time reading his publications? What if I just want to find someone that I've heard a story about so I can ask them more information? Should that be illegal? Remember, the people publishing these things publish them by their own choice with the understanding that they are making the information publicly accessible.

Dropping a bunch of names and recklessly implicating individuals in a criminal investigation is at least a civil offense, but there's no crime in drawing wild conclusions about people while cruising Facebook -- at least as long as you use the conclusions judiciously.