Wireless medical devices are potentially vulnerable to being remotely controlled by hackers and should be tracked more closely, according to a Government Accountability Office report. The investigation into electronic medical-device safety was initiated after computer-security researchers found dangerous vulnerabilities in insulin pumps. Diabetics rely on the pumps, which are worn next to the skin, to dispense insulin, a life-saving hormone. Representatives had asked last year for the GAO report, which called on the Food and Drug Administration to oversee better identification and investigation of security problems in electronic medical equipment.