Fraudsters are masters at manipulating their victims—especially seniors. They can persuade someone to give them thousands of dollars for some bogus reason: whether it's to claim a sweepstakes prize, help a loved-one in distress or to strike it rich with a "guaranteed" investment opportunity.

An employee at the bank or credit union might suspect something is wrong when a customer makes an unusually large withdrawal, but they may not say anything because of privacy concerns.