The Federal Trade Commission in December plans to hold a workshop to investigate the privacy and security implications of facial recognition technology. The agency announced this week that the workshop, which is free and open to the public, seeks to bring together consumer protection groups, privacy experts, and industry and academic leaders. The meeting is expected to address such topics as whether consumers should consent to the collection and use of their images. Facial recognition products can provide an added security layer at places like airports or automate photo tagging on sites such as Facebook, but critics worry they also could be used for intrusive surveillance. As a result, offerings have emerged that can help people hide their faces from the technology.