In a 2012 episode of the TV series Homeland, Vice President William Walden is assassinated by a terrorist who hacks into his Internet-enabled heart pacemaker and accelerates his heartbeat until he has a heart attack. A flight of fancy? Not everyone thinks so.

Internet security experts have been warning for years that such devices are open to both data theft and remote control by a hacker. In 2007, Vice President Dick Cheney's cardiologist disabled the wireless functionality of his pacemaker because of just that risk. “It seemed to me to be a bad idea for the vice president to have a device that maybe somebody on a rope line or in the next hotel room or downstairs might be able to get into—hack into,” said the cardiologist, Jonathan Reiner of George Washington University Hospital in Washington, D.C., in a TV interview last year.

Medical devices such as insulin pumps, continuous glucose monitors, and pacemakers or defibrillators have become increasingly small and wearable in recent years. They often connect with a hand-held controller over short distances using Bluetooth. Often, either the controller or the device itself is connected to the Internet by means of Wi-Fi so that data can be sent directly to clinicians. But security experts have demonstrated that with easily available hardware, a user manual, and the device's PIN number, they can take control of a device or monitor the data it sends.

Medical devices don't get regular security updates, like smart phones and computers, because changes to their software could require recertification by regulators like the U.S. Food and Drug Administration (FDA). And FDA has focused on reliability, user safety, and ease of use—not on protecting against malicious attacks. In a Safety Communication in 2013, the agency said that it “is not aware of any patient injuries or deaths associated with these incidents nor do we have any indication that any specific devices or systems in clinical use have been purposely targeted at this time.” FDA does say that it “expects medical device manufacturers to take appropriate steps” to protect devices. Manufacturers are starting to wake up to the issue and are employing security experts to tighten up their systems. But unless such steps become compulsory, it may take a fatal attack on a prominent person for the security gap to be closed.

For more on privacy and to take a quiz on your own privacy IQ, see “The end of privacy” special section in this week’s issue of Science.