Senator Al Franken expressed concern this week with the way Uber’s privacy policies remain unclear, in the wake of criticism over the company’s use of customer data.

“I recently pressed Uber to explain the scope, transparency, and enforceability of their privacy policies. While I’m pleased that they replied to my letter, I am concerned about the surprising lack of detail in their response,” Franken said in a statement. The senator chairs the Subcommittee on Privacy, Technology, and the Law.

“Most importantly, it still remains unclear how Uber defines legitimate business purposes for accessing, retaining, and sharing customer data,” Franken said. “I will continue pressing for answers to these questions.”

Franken’s letter, dated Nov. 19, addressed reports that execs had planned to dig up dirt on critical journalists, and that employees had abused Uber’s “God View,” which shows the location of all of Uber’s cars, to spy on riders’ whereabouts. In the letter, Franken listed 10 specific questions, ranging from what happens to customers’ data after they delete their account, to what training is provided to ensure employees abide by company policies.

Uber’s response to Franken’s letter described how the two incidents violated company policy. In particular, Uber clarified its policies regarding “God View,” stating that it is available only to certain employees, such as those working in operations. The company also said that recent press articles have “continued to generate misperceptions about how Uber employees treat the personal data of Uber riders.”

Contact us at letters@time.com.