“First and foremost the ATF 4473 is completely private. It’s treated the same as a tax return and cannot be shared with anyone not even a federal agency or state government.”
Theoretically, at least.
Assuming ALL the gatherers & keepers of this info are honest, not commie activist saboteurs.
As the poster above noted that isn't accurate. ATF and other law enforcement agencies have access to the 4473 forms stored by firearms dealers.