A report says Iran-linked hackers and related adversaries exploited commercially available cellphone location data to help target or surveil U.S. personnel overseas. Lawmakers cite warnings from U.S. Central Command that foreign adversaries were using purchased location information to identify theater activity and “patterns of life.” The concern centers on data brokers that collect and sell smartphone-derived location trails generated through apps and advertising networks. Officials say existing safeguards have not fully addressed the counterintelligence risk posed by the location-data marketplace.