I doubt you'd be a fan of such Public Registries for other things....like say, mental illness diagnosis. anyone who is diagnosed with any mental status that includes possible violence as a symptom or medication side-effect must register with the Police, and be in a Public Database. Whats the harm in that, right, we law abiding citizens would then know who the crazies are.
Well, lets ask a Cop (Green32) if he's about.And I don't consider a police check to be a "criminal invasion" or a swat team, etc. That's your excessive attempt at distorting to serve your stance.
If a citizen calls in and reports his neighbor is currently "acting erratically in plain sight", is "making (you) very nervous by his actions", is engaging in "disturbed behavior" AND you report that he is "stockpiling guns"......what would the appropriate police action be?