Falling asleep behind the wheel is one of the leading causes of automobile death according to a 2012 Harvard study. Two million drivers nod off behind the wheel every day, annually leading to more than 7,500 deaths and 50,000 serious injuries.

Those are big numbers and potentially, big business. A story in the Telegraph shows how researchers are working to cut down on those numbers by incorporating electrocardiograms into seat fabric. Essentially the ECG reads your heart rate as you drive. When it drops below a certain level an alert will go off, giving the driver warning that they need to pull over. If the driver ignores the warning, technologies like active cruise control and lane departure guidance could kick in to get the car to stop safely. There is also some discussion of alerting authorities at the same time.

Admittedly, this kind of physiological monitoring isn’t new. Researchers have been trying to measure everything from eye-blink speed to lateral acceleration and steering wheel angle, to try to help prevent long-distance drivers from falling asleep behind the wheel. The problem arises when you transmit that data to other systems, or in this case, to authorities and potentially others.

Think of it like this: Say you are heading to a big presentation and running late. Your heart rate is elevated, breathing shallow, and blood pressure high. The car reads this and could think “heart attack,” alerting the authorities to your whereabouts. Additionally that data could be sold to your car insurance company–making you a risk–and potentially jacking your rates.

Of course, there’s always the question of security of the systems as well. Someone with the right skills and technology could theoretically hack the system and make the car behave in a way that puts the driver in danger.

While it could make driving safer, for these reasons and more, privacy advocates will likely raise hell if the technology ever makes it to the consumer. Combining medical data with location data could prove to be a rich trough for Big Brother fears and, while things are only in the developmental stage, technology like this is likely to face some tough criticism, even if it could help save lives.