For the record if anyone else gets messages they deem as threatening, or otherwise inappropriate, please find a member of staff to forward them to. Obviously we aren't mind readers who know all PMs being sent on the site without prior knowledge, if something is over the line let us know. We take this site pretty seriously in terms of those kind of things.
Now granted the OP seemed to be looking for problems from the start with asking about blocking posters in like his second post, but we do strive to thread the needle between a safe place to post, and a pretty open exchange of opinions and viewpoints.