May 14th, 2021 Bill Clark via Getty Images The Pentagon may be using commercial data to track Americans without due legal process, according to a letter from Senator Ron Wyden shared with Vice News. Wyden had queried the Department of Defense (DoD) about mobile location and other data it had purchased from commercial sources, following reports in The Wall Street Journal and elsewhere. The DoD replied to some questions, but several responses were redacted. "I write to urge you to release to the public information about the Department of Defense's warrantless surveillance of Americans," Wyden replied. Various US law enforcement agencies have been purchasing electronic cellphone and other location data from apps installed on Americans' phones to track alleged terrorists, illegal immigrants and other groups since at least 2017. "I have spent the last year investigating the shady, unregulated data brokers that are selling this data and the government agencies that are buying it," the letter reads.