Anyone who keeps his money in a bank that deals in interest is sinning. There are several Islamic banks in Muslim world, from East to West. It is then incumbent on every Muslims to swiftly withdraw their money from interest banks and deposit it with an Islamic bank. Doing this, would save him from committing sin.
Regarding the previous benefits, it is usury (Interest) which is unlawful. Therefore, a Muslim must get rid of it through giving it to the charity and benevolence ways. If he found poor people then he can disburse it to them too. In fact, it is proper that the owner can benefit from it if he is poor and in need of it. It is not reasonable to order the owner to give it to the poor when he is one of them. However, a Muslim must repent to Allah, the most high, and avoid looking for unacceptable reasons to justify depositing in a bank that deals in interest. Whoever seeks for repentance and reform himself, Allah will grant him Forgiveness.