The result of this data breach is that anyone with this information will be able to pretend to be you and apply for credit in your name at any time in the future. There is only one way to guard yourself against this possibility: Lock down your credit.
Even if you think you have good credit, periodically check the facts on your credit report anyway. Your credit report will outline your full credit history. And it can help you verify you have not been the victim of identity theft.
As well as general online security, which includes a unique user name and password, and a system which locks you out if you guess the combination more than twice, Schwab has several optional verification methods.