A California company confirmed that a flaw in its website allowed outsiders to pinpoint the location of mobile phones in the United States without authorization. But LocationSmart, which gathers real-time data on cellular wireless devices, says it has no evidence that anyone exploited the vulnerability before May 16, when a security researcher at Carnegie Mellon…

For the first time, the U.S. government has publicly acknowledged the existence in Washington of what appear to be rogue devices that foreign spies and criminals could be using to track individual cellphones and intercept calls and messages. The use of what are known as cellphone-site simulators by foreign powers has long been a concern,…