PhysOrg reports that

A facial recognition database compiled by the FBI has more than 400 million images to help criminal investigations, but lacks adequate safeguards for accuracy and privacy protection, a congressional audit shows.

The huge database—which enables investigators to search images to match those of criminal suspects—"is far greater than had previously been understood" and raises concerns "about the risk of innocent Americans being inadvertently swept up in criminal investigations," said Senator Al Franken, who requested the study.