Is it true that GPS receivers in consumer grade devices automatically disables itself when it suspects it’s being used in advanced weaponry? It definitely seems so. The limits set by CoCom were established: anything faster than 1,000 knots (1,900 km/h or 1,200 mph) or higher than 59,000 feet (18,000 m) was regarded as a weapon. Most likely, an intercontinental ballistic missile.