Entire populations have been wiped out on the basis of _much_ less invasive data-gathering (eg. an innocuous question about faith on a census). All forms of PII-gathering are potentially dangerous and needs to be regulated. Do we really need to have a discussion about "but what if we do it this way? " "what if we do it this other fractionally different way?".
https://www.annefrank.org/en/timeline/70/the-amsterdam-munic...