> How is the IRS supposed to know how much tax to expect from you? How is SNAP supposed to determine your eligibility? How is unemployment supposed to know if you're ripping them off or not?

How does knowing your religious affiliation help them with any of this?

They should follow the principle of least privilege. Why not use differential privacy?

I don't know why you understood my comment as saying government shouldn't have any data. I specifically replied to the comment about religion - there's no reason for the government to collect any data about that from individuals. Churches can report how many members they have if they want to. But it shouldn't be a question on the census.