Democratic Sen. Elizabeth Warren of Massachusetts has earned a reputation as a fierce consumer advocate. She's gone after big banks and financial institutions, but now she's setting her sights on credit-rating agencies. Specifically Equifax, which endured a massive security breach last year. Over 100 million consumers had their personal information, like Social Security numbers and addresses, compromised in the hack. Now Warren and Sen. Mark Warner, a Democrat from Virginia, are introducing legislation that would levy harsh penalties for similar types of security breaches at Equifax and other rating agencies. Last year, Warren sponsored a bill that would allow consumers to freeze their credit any time for free, a service that rating agencies, including Equifax, have traditionally charged for. (Equifax waived these fees for a limited time after the Sept. 2017 breach.) Warren spoke with Marketplace Tech host Molly Wood about her office's recent report on the Equifax hack and her proposals to combat the cyber threat to consumers.