Computer security experts are trying to assess the risk posed by a hacker group that says it stole data from an FBI agent, including mobile device and user details for millions of Apple iPhones, iPads and iPods.

The group "Anti-Sec" said it grabbed the data from an FBI agent's laptop earlier this year. The group says it has so-called "unique device identifiers" for 12 million Apple devices, along with personal information including device owners' names and phone numbers.

As proof, the group released 1 million of the device identifier numbers on the Internet. On Wednesday, Apple denied giving any of the information to the FBI -- and the FBI says there's no evidence that one of its laptops was compromised, or that the bureau had sought or obtained the data.

The episode raises a flurry of questions about digital security, consumer privacy and the potential for government to track its citizens.

Host Tara Siler talks with Jennifer Granick, director of civil liberties at the Stanford Center for Internet and Society.

More: 7 Things to Know About the Hacker Release of Apple Device Data