That's one reason Scientific American argued in December that the biometric revolution "makes possible privacy violations that would make the National Security Agency's data sweeps seem superficial by comparison." Much biometric data are collected without the subject's explicit consent — or even knowledge, says Jennifer Lynch, a senior attorney at the Electronic Frontier Foundation (EFF). Little is known about how it is used.
Security is at stake, too, because biometric data is hard (if not impossible) to revoke or replace. "Data breaches occur all the time — who might get control of that data?" says Lynch. "I think we should be incredibly concerned over this."