Can a bank go in your savings account and take money without your permission?

if your owing the back like you have an over withdrawn account yeah they can take what you owe to them out of any account you have with their bank Usually after several attempts to contact you/collect the funds the bank will exercise what is called the right of setoff. Which is a federal law saying that they can take funds out of any account that you are listed as an owner and collect for an overdrawn account.