Update: July 7
The legal guys (Fisher and Herrmann) covered this problem on Saturday on CNN. Both thought this was overzealous prosecution based on public emotion. There reports that the Facebook posting contained lines like "JK" and "LOL".
What if someone makes a threat in a comment on a blog (or forum)? Would Section 230 protect the host? Would it matter if comments were monitored?. Sounds like an important line of questions.
Update: Dec. 5
Here is a case in Maryland where discussing an attack against judges on Facebook contributed to a conviction and prison sentence, WJLA story here.