Face-mask recognition has arrived—for better or worse. New algorithms can police whether people are complying with public health guidance. The practice raises familiar questions about data privacy.

Facial recognition is becoming more and more common, but ask anyone how to avoid it and they’ll say: easy, just wear a mask. In the future, though, that might not be enough.

Face recognition software can now see through your cunning disguise – even you are wearing a mask. Amarjot Singh at the University of Cambridge and his colleagues trained a machine learning ...