I know it’s cliche to bring up in these examples but there was an unintended negative outcome to Germany requiring people to register and pay some of their taxes to their church before ww2. The Nazis used that information to collect up and brand Jewish people and ultimately kill them. It is hard to imagine this tech will solely be used for good forever.
Los Angeles police already use gang databases to fault people for being in the "wrong" part of the city based on their database entry. This stuff is gonna turn into some kinda crazy 21st century internet apartheid.
