A few comments of my own here:
1. If you're going to blanket ban posting of any factual, negative situations - poor service will continue and the vendors practicing it and we the people won't know about it.
2. If you ban negative comments - for fear of defamation risk - ban positive comments - for fear of damages of folk acting on "expert" or informed advice that proves wrong - can create a situation for a claim in law against the offerer of the advice.
Example - say "Ronda gave me great service, she will always give you great service, her warranties are terrific, her gear never breaks or has any problems" - you have openned yourself and and IIS to just as much risk as saying "Ronda lied and cheated and stole my son and she'll steal yours too!" (if its not true nor spectulative).
Let's say you praise vendor X and attribute things to them broadly - I act on your advice and its wrong and I suffer collateral loss - then I have a claim against the vendor, you (for providing me wrong advice - yes really in law I do if I can reasonably consider you an expert) and possibly IIS!
If you stick to only saying what is clearly true then there isn't risk. If you say only speak happy, happy experiences - well you dilute the usefullness of the forum - and you open it up to just as much risk as saying negatives things in a non factual way.
My suggestion is only to speak factually. When I had troubles with vendors - service attitude mainly, or not keeping me informed - well eventually things got worked out and their service improved. Had no one said this could be better - I doubt they would have been aware of the problem, nor be enabled to fix it - to everyones benefit.
My suggestions are - keep it factual and non emotional. If you want to add a emotional contect - keep that personal to how you felt - example - it was really crowded, I was kept waiting 15 minutes whilst everyone else was served and that made me feel small. Those are two factual statements - waiting time and your own internal state of mind. No one can sue anyone over describing factual events. Ronda kept me waiting because I'm better dressed than her - is on the other hand spectulative.
Censorship doesn't stop the factual relating of a true experience - just write truthfully and don't spectulate. Saying vendor X promised A, B, C and lied once, twice, three times - is dynamite - but what if it's true - we want to know, likely they will hurt us too - if its false - you've defamed someone and hurt them and potentially us too.
PS
"As a result, if anyone initiates a thread or posts a comment critical of a vendor, the moderators have been instructed to lock and/or delete same." - well sorry the horse has already bolted - and performing that action may open IIS to another sort of claim. You see if someone defames me - then you delete the thread - you make it harder for me to sue them. It is a discoverable event, if I invoke a legal warrant to get your logs and you have deleted them you can be in trouble - you must produce evidence of what was said about me - failure to produce this evidence - or its deliberate destruction - for whatever reason - makes it harder for me to claim in law against this party - so now I have a different claim against you Mike and moderators for enacting this "destroy evidence" advice - even if its intended so many folk don't see your defamation of me! You server's, their back-ups, all logs are discoverable - at a cost to you, under my (limited) understanding of Australian law. If you get a legal demand to produce evidence and you say can't do - I destroyed it - oh the pain!
Instead you should move this thread /or post to a controlled forum section say that only moderators or defendants in the disputed case can see. That way you have not destroyed "legally discoverable evidence" - as certain other Australian forums found can cause a sting and you have limited the chance of any legal action.
Simple rule -
never, ever destroy what has the potential to become a legal document of evidence (remember what happened to Andersen's when not only they defrauded - they shredded documents - it was the shredding that sunk the firm).
PPS
If you want to discuss bad service - post on
http://www.notgoodenough.com/ and ask the moderators if you can link to it here.