John,
I always enjoy reading your articles as well as the comments posted. It is unfortunate that you have been threatened with legal action over comments posted by others. You can take comfort in the long established legal principles which protect you. There is an extremely high threshold for a public official to achieve in order to prove libel or slander.  The public has long had the right to lob verbal handgrenades at it's officials without fear of legal assault.
I would rest easy!

John Martin

(a former public official and recipient of a number of such "handgrenades")