Well, by making such service, you destroy scammers "business" ... so they will be a bit angry and try to DDoS your server to prevent users going to your website and force them to trade again in "old way" ... with scammers. You see ?

At least this was my supposition. That's why I didn't make a website.

Yes bitcointalk can be DDoS too. But if they do this, they can't scam anymore themself, a bit stupid.