I understand why the mods made their decision, but I disagree with it. I've also seen some of the mods use the threat of retribution to stifle debate, aqcusing posters of making personal attacks or breaking the rules and warning them, when the poster is attacking a mod's arguments in the course of a debate. I would suggest two guidelines:
1. When an admin locks, deletes, ghosts etc a thread, they leave their handle so there is some accountability and the OP can contact back (i.e. through PM) to get a clarification. In Marco's thread, I had no idea what it was about, and wouldn't have known that drug legalization was out of bounds for thread topics, except I PM'd him.
2. Admins should not rebuke posters for a post that is directed at the admin, within the course of normal discussion. If a poster challenges an admin while the admin is moving threads, moderating, etc. then by all means. But when an admin is acting as a poster, there is at least a strong appearance of impropriety when that same admin threatens a challenging poster. We all get attached to our arguments and sometimes its easy to take a substantive challenge personally, and thus over react.
That's just my two cents; generally I think the mods do a great job on the board, there is always lots of talk, and you can usually count on a heads up before more serious action occurs. And we don't really have a lot of junk on the site either, which is great.