satellite navigation such as GPS devices, and that the results can be... dangerous. Anyone with a think tank could probably figure this one out on their own, but the research shows that such over-reliance on the devices can produce some bad results when said devices inevitably fail out. The report goes a lot father than warning individual drivers, however, and says that systems such commercial airline traffic and those which direct train doors to open also rely on the US-based GPS system, which are all vulnerable to widespread failure should the system encounter any interference or downtime. The report does suggest further development of backup systems -- such as the European-based Galileo system, but essentially concludes that the vulnerabilities are likely to remain. Comforting, huh?