Impossible to track tattoos. The owner can get a new one any time. Do they propose registering each new ‘too? Does the artist have to send a pic of the design to the Feds? GIF or JPG?
Not impossible at all. It’s just an extension of facial recognition software. They don’t need to register them, just they look good in any kind of ID/ line up photo so they can land in the database and be used when they’re checking through surveillance footage.