In a sane world, such an idea would never be spoken. No one who knows liberals expect them to be sane!
Few gun owners of today will remember but they demanded, and got, a silly ammo listing provision in the totally stupid Gun Control Act of '68. It required every sale of ammuniton, except shotshell, be recorded, stating who purchased it, his address and the caliber. The "common sense" justification they gave for such a foolish requirement was the cops could quickly run to all selling points and comb through the files to find everyone who had purchased ammo in the caliber used by some crook. Of course it failed, never heard of a single case of a crime being assisted by it. Part of their problem was the forest of data quickly became so vast no cop agency could possibly find a relivent tree, so it ended up making the cops look foolish that they couldn't get any useful data from all those records. The BATFmen eventully asked congress to delete those listing requirements and it dropped into its proper oblivion.
It won't work, again. But, those liberals who dream of an idealised world with themselves in control of us peons won't be put off by facts. They plan to take a chance on it, again. And we law abiding gun owners will get shafted, again. And pay for the liberal's stupidity, again. It's just the Democrat's way of showing how much they love us and want to take care of us. And for the children, of course.