A senator is demanding that the FCC investigate why a company, contracted to monitor calls of prison inmates, also allows police to track phones of anyone in the US without a warrant.

The bombshell story in The New York Times revealed Securus, a Texas-based prison technology company, could track any phone "within seconds" by obtaining data from cellular giants -- including AT&T, Sprint, T-Mobile, and Verizon -- typically reserved for marketers.

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The report said former Mississippi County sheriff Cory Hutcheson used the service nearly a dozen times to track the phones of other offices, and even targeted a judge.

Hutcheson has pleaded not guilty to conducting surveillance without court orders.

Securus provides the location-tracking feature for law enforcement and corrections officers, the report said, which helps locate individuals who abscond from justice or are missing.

Sen. Ron Wyden, a Democratic senator from Oregon whose work often focuses on tech and privacy, sent a letter to the FCC this week demanding an investigation.

Wyden said the system allows police and government employees to conduct unauthorized and warrantless surveillance, and it "needlessly exposes millions of Americans to potential abuse and surveillance by the government."

Securus said it required an "official document giving permission" to obtain real-time location data, but Wyden's office said that Securus officials make no effort to verify the purported authorizations.

Securus provides this real-time location data through a self-service portal for police, said Wyden, for "nothing more than the legal equivalent of a pinky promise."

Wyden also sent letters to the cell carriers demand answers. In the letters, the senator said the carriers "not sufficiently control access" to their customers' private information.

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In a blog post, the ACLU said the system is "ripe for abuse."

"The FCC should also immediately investigate Securus and any companies that provide similar services. It should make clear that this conduct, which essentially coerces individuals into 'consenting' to location tracking or other surveillance, and which fails to confirm the validity of search warrants before tracking people's cell phones, raises serious questions under existing federal law and must be halted," the post read. "Additionally, they must take steps to ensure that telecommunications providers themselves adequately safeguard data from this type of abuse."

The cell carriers are investigating, the report said.