If the government said "let's make a database of every Jew in America," people would get rightfully riled up. Yet we've allowed a single entity to assemble a database orders of magnitudes more detailed.
You can see the early fruition of this by looking at how useful Google Now/map planning etc are.
Computers could be our all knowing assistants.
That's on a very surface superficial level.
Imagine the kinds of benefits when this all knowing entity is applied to medical issues. Real substantive progress could be made.
However, today's mismanagement of data could scare people off all knowing entities for good & end up severely limiting real progress.
As with everything else, all that data is rife for abuse if the necessary legislation & technical limiting/auditing regarding access/use are not first put in to play.
This is an interesting case. You're completely correct, but it's basically a special privilege that Jews enjoy (and that has spread to a taboo on asking about religion on the census). If you're part of any other demographic group and you don't want to be counted, you get yelled at for not seeing the grand scientific project of the US census in the proper light.
But I don't really see that a database of every Jew in America is more inherently suggestive of abuse (if you're a Jew) than a database of every black in America is (if you're black).
Any group with (a) a living memory of violent ostracisation and (b) some ability to conceal their group membership knows this.
Gay men and women, for example, would fight against a sexual orientation question on the census. (One wonders if Tim Cook, had he not been born a gay man in Mobile, Alabama, would be as sensitive to privacy issues.)
Side note: I used Jews in my example because we have a case study for them. In countries where databases of religious affiliation were kept, oftentimes for tax purposes, the Nazis took advantage.
> For the LGBT question, the exact opposite is happening: People who want a head count of gays and transgender people believe the data will then be valuable in influencing federal policies and spending on projects that benefit LGBT people—or, more accurately, to benefit certain LGBT organizations.
See also the effort by certain ethnic groups to split into a special MENA category on the census, despite having passed as white successfully for the last entirety of history.
It's not about ability to conceal group membership.