Social Security (SS) numbers were used by IBM to keep track of US citizens even before they helped the Nazis in keep track of undesirables.
Oregon, August 1939. “Unemployed lumber worker goes with his wife to the bean harvest. Note Social Security number tattooed on his arm.” Oregon, Marion County, near West Stayton.
Tattoos are no longer necessary for most US inmates. Facial recognition, driver’s licenses, DNA, fingerprints, and ubiquitous surveillance cameras and restrictions will help locate you wherever you are.