I have negatively rated a company in my own state for
non-payment.  Ironically it was with a company who used
to be on this message board always complaining themselves
about non-payment and stated that they were starting their
own collection agency.  The reason I did the orders was because
I saw them on here, thought they would be reputable as far as
payment since they knew what it was like.  I did the work in
November and still have not been paid.  I also never see the
person posting earlier from that company, on here anymore,
though they do still advertise on SOT. I think that at least posting
messages like we do does help.  I have been called by several of
the companies who have had threads about non-payment, and I
just stay away.  I have enough unpaid work on my books!  I am glad
for this site, I feel it helps me stay away from some of the companies
who hop around from searcher to searcher not paying anyone. 
The posting about the ASK that used to advertise here and had
negative ratings, then disappearing is interesting, since I personally
know several people that they owe thousands of dollars to! I am
glad for the heads up we give each other about some of the shadier
companies.