Authorities are trying to determine how a hacker gained access to a University of California computer that contained personal information about more than 1 million people, many of them recipients of an assistance program for the elderly.
The FBI, the California Highway Patrol and the California Social Services Department have not determined whether any personal data was taken, but officials said they have not seen any evidence of identity theft.
The computer contained home addresses, telephone numbers, dates of birth and Social Security numbers. Many of the people listed were enrolled in In-Home Supportive Services, a state and federally funded program to assist elderly and disabled California residents.
A researcher at the university's Berkeley campus was authorized to work with the data.