When government wants to round up the guns it needs to know where they are so they keep lists of the people who have them. It makes it so much easier to keep the goverment safe from the people.
The Second Amendment explains the government is forbidden from making laws about guns. The Fourth Amendment forbids government from searching private papers. Between those two protections is where a citizen can live safe from the government. Those are elements of Liberty that are unique to America. No other nation has ever done that. Unfortunately, the American government has betrayed the Constiution with over 50,000 laws against guns and by keeping lists of people who own or may own guns. Even worse, the names and home addresses on those unconstitutional lists are available to people who want to harass people who want government to be controlled by the people. Some people want to at least, defend themselves. Government believes that’s a danger to it. Self-Defense against Government is not popular with government and government has slowly eliminated the prohibition of government. Can you think why that’s important? No? You don’t deserve to be free. Unfortunately for those who know about Liberty, you are a danger to freedom.