The BBC reports Royal Academy of Engineering concerns that the UK is dangerously over-reliant on satellite-navigation signals. A cascade of failures could result from man-made causes, such as deliberate jamming, and natural hazards, such as solar activity: "Use of space-borne positioning and timing data is now widespread, in everything from freight movement to synchronisation of computer networks. The academy fears that too many applications have little or no back-up. ...There is a growing interdependence between systems that people think are backing each other up. And it might well be that if a number these systems fail simultaneously, it will cause commercial damage or...loss of life."