Yes but NEW people to the forum and such wont know that will they, and there will ALWAYS be new people.
So your saying just let them scam people then those people will learn, but then they get new victims and it just goes on.
I would put money on it that if there was actually dedication into stopping these then the number of scammers would go down a lot making life even easier for admins.
Those specific forums you have set up are dedicated to trading, but where they are just full of scammers now like 1 in 10 are actually genuine posts.
The scammers in a way is your responsibility too as you set up the trading forums, people do need to be cautious when trading online yes. But when 75% of the posts in trade are scams then what kind of reputation does that give to sythe on the new guys joining. People search things on google such as 'wow wotlk beta key' lets say they get a search on these forums so they come here go to trade and someone attemps to scam them so thats that.
But if it was successful then they would come back.
There's things that can be done if the people at sythe actually put work into it.
For example make rules like people with a certain amount of posts or/and havent been registered for however long cant post any selling threads.
Because at the moment its really not hard to try and scam, you make an account you make a post, done and just wait, and people such as me are new to the whole MM scene, in my case a MM was added to our convo but turns out it wasnt a real onem i caught him out, he had a very similar email to the real one, another person might not spot that.
Scammers are everywhere its down to people not to get scammed but its also down to the admins to get rid of the known ones not just do anything.
Look at ebay they always have scammers on there but they get rid of known ones fast, people cant sell without having bank details and things like that.
You could even make people that want to sell on the forums have to use this:
http://www.trustwho.com
Also the IP ban should be implemented the first time they scam not 2/3 time that's just stupid. A scammer is always a scammer same as a hacker on a game is always a hacker like 99% of the time.