This system seems ripe for exploitation. Banks 'clear' checks by granting the account holder access to the funds they expect to be available. A check can still be bounced or returned days or even weeks later in the case of fraud.<p>This is how a very common scam works. Receive a check written for more than you were expecting (usually for the sale of some goods or as prepayment for a service). Receive instructions to deposit the check and return the difference to them (with a healthy profit for your troubles). Weeks later, the check bounces and your account is debited the amount of the check, while the scammer has the cash you wired to them. Essentially, the scammer uses your good standing with the bank to cash a bad check.<p>Given the nature of this system, what's to stop someone from depositing a bad check, emailing the receipt, and receiving BTC after the funds are released but before the check actually clears (or rather, bounces)?