By Ian Bush

PHILADELPHIA(CBS) – Forget fingerprints. The FBI is reportedly building a database of faces, using public surveillance cameras, to help agents identify suspects wherever they go. But the feds aren’t the only ones who want to track you.

The billion-dollar, nationwide effort is called Next Generation Identification. New Scientist reports it’ll include face and voice ID, iris scans, and DNA analysis.

“In the end, it will hopefully allow law enforcement to more efficiently solve criminal investigations,” says Dr. Rob D’Ovidio, associate professor of criminal justice at Drexel University.

For him, the biggest question is what the FBI does with data that doesn’t match suspects’ IDs.

“The best-case scenario when it comes to privacy protection is that an image would not be stored after it has been determined that there is no match of it in the database,” D’Ovidio says. “If they’re retained, those people going about their everyday lives not doing anything criminal run the risk of the government being able to re-create their travels and understand patterns of behavior.”

He says Congress must put in place restrictions on how long such information can be kept, and the White House must ensure the FBI follows those rules.

D’Ovidio cautions that the similar facial recognition technologies are available to places like malls, banks, and other buildings where cameras are rolling.

“The scary thing is that there is much less oversight of the surveillance practices of these private entities than there is over government agencies,” D’Ovidio says. “We have limited ability to put those same safeguards into place when it comes to private entities that are capturing these data.”