I recently also experienced strange trades via bank transfer, when selling. There are a number of indicators, that the person is not the one he/she claims to be, even though they seem to have access to the bank account and copies of passports. In 2 cases, where I am not yet sure if they are fraudulent, the buyers had an account from a charity organization. Each time, the account was also freshly created and had no history. Answers were sometimes rude, when too many questions were asked. I fear that there might be police investigations following the trades, due to stolen identities and online banking credentials.