One of the things that blows my mind is that we can't find common ground on using modern technology to create a background check system that allows private owners to run a check on a buyer without allowing the government to turn it into a registry (as has been noted, a lot of gun owners took the confiscation scene in Red Dawn seriously, and some of the rhetoric coming from anti gun activists reinforces the notion; registration is a nonstarter for many, many gun owners).
At the same time, many gun owners want to be able to sell stuff while minimizing the chance that the stuff they sell will be used in a crime.
We could do this with a system where the seller has the buyer log into a website, the buyer puts in their info and the seller's email, and the seller gets to login to download a PDF confirmation that the other guy is an eligible buyer, plus an encryption key they download.
The encryption key is then used to encrypt the government's record of the check, and the government doesn't retain the key. In the event that a gun is found in the hands of a prohibited person, the government goes to the FFL who sold it, who then uses the encryption key to pull up the buyer info, and the process repeats until someone can't show they did due diligence before transferring the weapon.
If the Russians or the Australians invade, everyone deletes their copies of the encryption keys and then no one can access the data.
I would also favor your firearm being misused being prima facie evidence that you were negligent in caring for it, with something like a police report indicating B&E and it being taken working as an affirmative defense.
