I would suggest that you stop selling bitcointalk accounts.
Mostly scammers buy accounts to scam people with the registered date.
I don't see any benefit in buying accounts if your honest/trustworthy.
This only benefits the scammers.
Yes What you said is true , he really must stop sell account to avoid scam/spam in the forum
He won't, it is a business venture after all and if someone scams or spams with an account they buy from him it doesn't negatively affect him at all. Just stating the truth.