To all the idiots in the thread saying the bank should never have let this happen: this is cashing a check and you want this to be possible so you don’t have to wait 3 days after depositing a check to access the funds.
A bank that’s done business with you trusts that you wouldn’t deposit a fake check and believes that the amount on the check is going to be available to be transferred.
Anyone abusing that trust makes it likely that the feature will be taken away from the rest of us, and they should see at least a week of jail time.