"Purchasers of handguns are also required to provide proof of California residency, such as a utility bill, residential lease, property deed, or government-issued identification (other than a drivers license or other DMV-issued identification)."
Might as well give them a pint of blood and a semen sample too.
charge you for the handgun safety course...
charge you for the background check
charge you to renew your "handgun safety cert"
I hate CA for their nanny law bullshit, but that's some sexy upfront/residual income from all firearms owners.