The iPhone X only drops in November, but the United States Senate is already curious.

Sen. Al Franken, Democrat of Minnesota, sent a letter to Apple chief exec Tim Cook yesterday asking him to clarify privacy protections for the tech giant’s new flagship model. Announced earlier this week, the $999-plus device comes with FaceID, or facial recognition technology that automatically unlocks the iPhone upon identifying the owner. Citing concerns from privacy advocates and journalists, Franken wants to know more about how the world’s most valuable listed company uses the biometric information and how Apple plans to cooperate with unlocking requests from law enforcement authorities.

The ranking member on the Judiciary Committee’s subcommittee on Privacy, Technology and Law notes that fingerprints and facial recognition data differ significantly from passwords because it’s relatively easy to alter the latter. While Phil Schiller, a top lieutenant to Cook, has said that FaceID data would be stored locally on the iPhone and that chances of an unauthorized person unlocking your device are 1-in-a-million, the senator wants to know if and how Apple can access the information, and what other commercial use it has planned for the data.

“Apple itself could use the data to benefit other sectors of its business, sell it to third parties for surveillance purposes, or receive law enforcement requests to access it facial recognition system – eventual uses that may not be contemplated by Apple customers,” Franken wrote. “It is incumbent on Apple to provide as must transparency on this complex new technology as possible.”

These questions aren’t merely hypothetical. In recent years, Apple has received numerous orders issued by U.S. District Courts compelling the Cupertino, Calif. company to help law enforcement authorities unlock iPhones material to prosecutions. Apple has challenged those writs and indeed, a New York magistrate judge ruled in its favor. The Obama administration dropped its appeal after it said it’d found a way to unlock iPhones without Apple’s support.  Now, Franken wants to know if and how Cook will cooperate with authorities when it comes to accessing data protected by facial recognition technology.

Also read: This is everything Apple quietly did away from the iPhone X’s spotlight 

The senator also requested more details about the sausage making behind FaceID. In his letter, he asked Apple for more information about how it was developed, noting that the company said it trawled through 1 billion images while creating the technology. Franken also wants to know if Apple has taken steps to ensure a diverse range of faces are accommodated for. There is some evidence that facial recognition works better for white faces than it does for say, Asians and Blacks.

Since being elected to the Senate, Franken has positioned himself as a keen defender of consumer privacy. Last year, he asked Niantic, the developer of Pokémon Go, for details on how it collected user location data and how it was used.