Ignore list.
Advise posters they have been placed on an ignore list and who the anonymous poster is that has done so.
1. If a poster gets too many he may realise that he is not flavour of the month generally speaking and as a consequence may apply more thought to what he is saying.
2. In order to prevent ongoing discourse and unwarranted ignore, ie ganging up, if a poster ignores someone it becomes valid for two weeks and the ignore cannot be removed.
This stops you ignoring someone and then sneaking back for a look and carrying on as before.
I am guilty of this.
It would also make you think before ignoring someone in the first place which may make the ignoree in turn think about what he/she has said.
Just a suggestion, ignore it by all means.