Glenn Reynolds declares that a private listserv run by Ezra Klein is a “scandal”. Which is interesting, because I first ran into Glenn Reynolds on a private listserv run by Eugene Volokh. The members included pro-gun law professors like Reynolds, an NRA staffer and at least one journalist. I do not consider Volokh’s listserv to be a scandal.
Volokh converted it to a public listserv in 2003 and traffic dropped significantly after that, though that might be a coincidence.