Comment Re:They didn't think of this? (Score 4, Informative) 41
GPS Spoofing has been a known issue in both the GPS and flight safety industries for a long time. There were debates around it when ADS-B was rolled out but they weren't taken seriously because it has never been a significant practical issue.
The military GPS bands have a code that encrypts the signal, this prevents spoofing for military users. The catch the military has is that the military equipment is rare and fairly shit compared to the civilian equipment. In desert storm soldiers were relying on civilian equipment procured personally and by the military. My understanding is that this is still the case, soldiers carrying Garmin watches for example. So the military is still impacted by spoofing, despite the military band.
My understanding is that most of the current spoof attacks are fairly crude and can be detected by looking for discrepancies between the signal over time, signal strength or between the multiple bands and systems now available. However once detected you've still lost GPS and it's now a critical component for many industries.