As I've been admiring people's builds on this and other sights, I've noticed pics where people cover or deface the serial number. Why? Is there some power to having the serial number? It's not like a SSN or something. And unless you bought your weapon from a private party, the govt already has the serial # linked to you. They're not supposed to keep a registration of owner to weapon, but we know they do. So is there a good reason to hide your serial nunber?