If I knew for sure that a user is a scammer, maybe because he has been banned from Sythe, would I risk getting banned if I have the opportunity to scam him and I do it?
I agree on that, I've been scammed many times as I just got on Sythe but I am trying to build a reputation here being honest in every trade. The fact is that the user has clearly admitted on Skype that he has scammed, plus his Skype contact is in the scammers list and there is a report thread against him. He doesn't even seem to feel any guilt for scamming and will probably scam again.
It's not even about the fact that I want to scam him for the money (less than 10$), it's more about the satisfaction to get revenge for his innocent victims.
Waiting for a staff post anyway, not going to risk a ban if it's forbidden by the rules.
I don't think it's allowed. However, if you know that this person recently scammed someone on Sythe and traded you it (they scammed someone 500m and sold you 500m) you may return it to the person who got scammed.
you may scam a scammer, only and ONLY if there is sufficent evidence of scam that led to their ban on this forum or another. ALSO YOU MUST GIVE THE STUFF YOU SCAM TO THE VICTIMS WITH PROOF . DO NOT TRY TO SCAM AND SAY YOU DID REFUND AN YOU KNOW YOU WON'T CONTACT HIM.