If the password changes when the account is sold, tell the person that made the positive trust that the account had been sold so they can remove it
Please also let us know so we can burn it's trust rating for being a bought account which, by default, is only purchased in order to deceive other forum users. This means the person operating that account is provably dishonest and so it should be marked as such.
That is actually not true. Just because he bought an account doesn't mean that he is dishonest. He might just want to join a signature campaign and earn some extra money.