WASHINGTON (AP) — Five U.S. senators want Uber to tell them when it discovered a massive data breach and what it did to respond.

Uber disclosed the year-old hack last week. Taken were names, email addresses and mobile-phone numbers of 57 million riders as well as driver's license numbers of 600,000 drivers.

Four Republicans led by John Thune of South Dakota want to know when Uber discovered the theft, when it notified regulators and whether Social Security numbers were taken.

Democrat Mark Warner of Virginia wants to know why Uber didn't have better security.

Both sent letters to the San Francisco-based ride-hailing company Monday. Uber says it will address the Senators' concerns.

Last week, Uber said it paid the hackers $100,000 to destroy the pilfered data. It says there's no evidence the data was misused.