WASHINGTON -- Five U.S. senators want Uber to tell them when it discovered a massive data breach and what it did to respond.
. 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. You can read his letter here.
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.
Meanwhile, the company is being sued by the city of Chicago and Cook County on claims the breach harmed "tens, if not hundreds, of thousands" of area residents.
The lawsuit filed Monday in Cook County Circuit Court contends Uber's failure to protect consumers' personal information violated city and state laws.
The city and county are seeking a $10,000 fine "for each violation involving a Chicago resident."
Uber also faces lawsuits filed by consumers over the issue.
Uber spokeswoman Molly Spaeth said in an email to The Associated Press that the company is "committed to changing the way we do business."