Well, this can't be good, but it's certainly not surprising, either. Researchers have concluded that people living in developed nations have become overly reliant on 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?