I think, we must tell others if we have a confirmed information. In such way we can help each other and we'll be better informed. Noone wants to lose his money.
[/quote
If I come across with  scammers I definitely do what is right I will  notify  the brethren not to join on their project because it's very hard to be a victim  of scam. It's one way of showing  my concern to my fellowman.