Biometric technologies are still new and they are advancing rapidly. Laws are just starting to be created to address issues of privacy and ownership of biometric data. A few states have created laws and generally they say that a person must be notified if their biometrics are being collected and told how the biometrics are being used. The biometrics cannot be sold or used for any other purpose and they must be disposed of when there is no longer a need for them. But most states do not have any laws covering biometrics and companies are largely free to do what they like.
Neither these laws nor any existing laws prohibit government actors from collecting or using biometric information in connection with law enforcement, immigration, border security, or national security. Like most technology, biometrics can be used for good or evil. However, for security, forensics, fraud prevention, and a host of other applications biometrics are an invaluable tool. To protect privacy, the best option is to continue to push for government and commercial transparency and accountability.