Yes the Better Business Bureau thrives, but they do complete all the updating, reporting and investigating of the complaints. 

The question stills begs an answer, who is willing to do all that? 

Would it be unethical if the list was not updated and alledged complaints not investigate, contact not made with the offending party?  If not, anyone could put any company on the list for any reason and not just payment issues. 

Prior to putting a name on the list, would there be a requirement to prove the non-payment, i.e. copy of the search, copy of the order, copy of the invoice?

I believe this could become a slippery and dangerous slope for the keeper of this list.

Now before you get a bee in your bonnet, I am not saying all companies have excellent payment records.  In most industries there is a built in 2-3% bad debt.  That is an unwelcome part of running a business.  Sometimes it seems that ours is a lot higher and very well might be. 

All I am saying is be careful.  What goes around comes around.

Jay