The resistance movement in Norway, during WWii, targeted and blew up the citizen registry, because it was used for evil. Any database we build now could be used like that. Now they are easily copied, so we won't be able to blow them up when it's already too late--we must avoid building them.
Sure. They might outlaw brown hair, too. They might outlaw last names with vowels. That hypothetical, imaginary risk doesn't make it sensible to dye your hair and change your name.
Tell the 6 million Jews, hundreds of thousands to million+ Romanis, and hundreds of thousands of disabled who were systematically exterminated by gassing, shootings, starvation and various other means that being outlawed is a "hypothetical risk". Even beyond WW2 to say what you said is so incredibly against any form of historical understanding that one must start to wonder what your motive with it is.
