[ergl]

It's not far-fetched. Differential privacy is going to be used for the US census this year. Here's a report on it: https://arxiv.org/abs/1809.02201

Also, it's not a magical solution. Here's one of the issues from the linked paper (edited for clarity):

"The proponents of differential privacy have always maintained that the setting of the [trade-off between privacy loss (ε) and accuracy] is a policy question, not a technical one. [...] To date, the Census committee has set the values of ε far higher than those envisioned by the creators of differential privacy. (In their contemporaneous writings, differential privacy’s creators clearly imply that they expected values of ε that were “much less than one.”)

[DataWorker]

“In addition, the historical reasons for having invariants may no longer be consistent with the Census Bureau’s confidentiality mandate.”

us census, RIP