More and more self operating devices like cars and drones are coming to market and many use civilian GPS to navigate. Since GPS signals are not encrypted can this pose a threat? Can someone try to spoof GPS to control these devices to do malicious activities? Like stealing a car?
Yes, this is a danger. In 2011, Iran probably goofed on a US drone's GPS (<a href="https://en.wikipedia.org/wiki/Iran%E2%80%93U.S._RQ-170_incident" rel="nofollow">https://en.wikipedia.org/wiki/Iran%E2%80%93U.S._RQ-170_incid...</a>) in order to get the drone to land where it wasn't supposed to (in Iran). Further, the technology to do this is almost mainstream. Surveyors use something called "differential GPS" to get very accurate locations. I bet that differential GPS transceivers could be hacked to override, rather than just correct, regular GPS receivers.