Have to disagree with this proposal. If you start labeling people as potential scammers, you actually INCREASE the chances of them scamming people. You cause a self fulfilling prophecy. Consider the case of Occulta. Occulta appeared on bitcointalk late last year offering something that many people deemed too good to be true - amazon codes at 80% of their cost price. Occulta has since proven himself reliable and trustworthy - and i do not mean to question his honor here. But his case illustrates my point. Lets assume that not long after Occulta first appeared on these forums, he sells someone a $1000 code that for some reason doesn't work, and is then given the potential scammer tag. Lets also assume Occulta is midway through several other transactions, so that he is currently holding another $5000 which he has not yet sent the codes for. In this scenario, by giving Occulta the potential scammer tag, you severely reduce his incentive to follow through on the other transactions. When the bitcointalk lynch mob goes after him upon seeing the potential scammer tag - he may decide it is easier to just walk away with his bitcoins - then attempt to convince the mob of his innocence.
IMO the creation of a potential scammer tag would be a worrying development for these forums. The opinion of forum mods on whether someone is a scammer or not is very influential - particularly for junior forum members. As a result, forum mods have a responsibility not to exercise this power in such a way that it actively hurts legitimate members - such as by issuing premature scam warnings.
I totally agree with you, which is why I mentioned that the level of evidence must still reach that of the scammer tag. However, unlike the scammer tag, I'm proposing that this be applied while we wait for the person to compensate the person who was scammed.
But yeah, maybe it does go too far. It just pisses me off that so many people lost money just because we didn't label them as soon I we
knew that they were scammers.