Posting a bad trader etiquette question

I wanted to ask this question here as I feel it is applicable.

I am a member of various trading forums, and today I saw a post from a noob on one of the boards about a particular trader who hasnt fulfilled his end of a deal. The reported trader also posts at another forum I am a member of and has been reported neither good or bad on it, the one hes been reported on this is the first report of any sort. I bring up the noob part as it could be a vendetta or something as neither have any reputation on the board that the bad apple was reported.

Am I under the obligation as a responsible trader (which I feel I am) to let the people on the 2nd forum know that the person being reported has been reported bad somewhere else? Even without giving the potential bad apple a chance to respond publicly? Should I wait or stay out of it and not do anything?

Sorry if thats too wordy or muddy, typing as I think

[U2Lynne]

I guess I would wait and see if anyone else backs up the claims that the guy is a bad trader. That's what's nice about having a thread about it, because people can step in and say that they've had successful trades with the guy or that they have had the same bad experience. So, I'd wait and see what happens.