Facial recognition is fast becoming embedded in everyday life. But as it improves, the technology is raising new privacy concerns.

“Most American adults are in a face-recognition database accessible to law enforcement,” said Clare Garvie, a senior associate at Georgetown Law’s Center on Privacy & Technology, who studies the technology and its privacy implications.

Facial technology can now be found in more schools and retail stores to help identify people who may pose a security risk. Some stores are also using facial recognition in an attempt to determine shopper sentiment, giving retailers the opportunity to adjust their sales pitch. One company in Israel claims its software can flag potential terrorists by scanning facial features and expressions alone.

In this episode of Moving Upstream, WSJ’s Jason Bellini tests out facial-recognition systems at an elementary school in Seattle and at Florida’s Orlando International Airport. He finds the technology doesn’t always work as advertised.

Write to Hilke Schellmann at hilke.schellmann@wsj.com and Jason Bellini at jason.bellini@dowjones.com