Instead of paper or electronic tickets, some airlines now want to use your face as a boarding pass. At the 20 largest airports in the United States, the U.S. Customs and Border Protection Agency is implementing facial recognition systems for international travel. These systems record not only your face but also other biometric data, such as fingerprints and iris scans. The goal is to track all passengers from curb-to-gate. Hertz is also implementing facial recognition and fingerprint scans, which allow customers to check cars out in 30 seconds.  What type of technology covered in this chapter is being used to implement these new systems? What are the benefits of such technology to companies and customers? Are there any concerns for customers?