You’re filling out forms at a doctor’s office, hospital, or other healthcare facility and come to a line asking for your Social Security number. Should you write those nine digits down? Generally, no, say privacy experts. “Having Social Security numbers at the doctor’s office is a data breach risk, and it’s one that’s increasing,” says Pam Dixon, executive director of the nonprofit World Privacy Forum. If stolen, your SSN offers thieves easy access your personal health and financial information, and they could possibly steal your identity.