The best answer was probably the advice to check with legal counsel.
There have been numerous discussions of this question in this and other
forums (you might want to check the list archives), and the answer
usually seems to be "it depends". A short list of factors which might
be considered would probably include the following:
* the purpose of the list;
* whether subscription is voluntary or mandatory (as with a list used
  by an organization to communicate with its employees);
* restrictions, or lack thereof, on subscriptions;
* restrictions, or lack thereof, on postings;
* the type of entity which provides the hosting service;
* the nature of the relationship between the hosting entity and the
  list owner and/or editor.

On Thu, 8 Apr 1999 "Hugh W. Jarvis" <[log in to unmask]> wrote:
Does anyone have a good handle on the current state of the law for US
listowners's liability?