How would this “technology” be rolled out to almost half a billion firearms, some of which are over a century old and still very well fit for purpose?

Further, you do realize that you are fucking with a constitutionally protected civil right. Of course, that hasn’t stopped tyrants in the immediate past.

Also, it is important to recognize the difference between the Declaration of Independence and the Constitution of the United States. One is an expression of the hopes and dreams of a people desiring freedom and autonomy (life, liberty and the pursuit of happiness) and the other is the black letter law of the land. Nowhere in the Constitution are those three aims mentioned.