Even with a covered face, agencies are deploying "gait recognition", which fingerprints you based on the way you walk. Here's an article about China doing it but I'm sure the US is as well: https://apnews.com/bf75dd1c26c947b7826d270a16e2658a
also, its funny to me that how, most non-technical people share and complain about all the technological things china uses to detect and identify, and then don't even think that U.S. might have similar or even better tools.
Anyone else suffer from writers block because reality is stranger than fiction by a long shot these days?
You can defeat that with 4 or 5 pieces of gravel...