Is a person sinful merely for owning a bank account that he does not use and that is empty of money, knowing that the bank deals with usury?

It is permissible to deposit money in a Riba-based bank without interest if no Islamic bank is available, due to the necessity of preserving wealth. However, if an Islamic bank is available, then it is not permissible to do so, as it constitutes aiding in sin. As for opening an account without depositing money, there appears to be no prohibition against it if it is for a need and not in vain.