it's been a law in many states for some time now, that you must register the weapon when you purchase or transfer it, I never had a problem with it, nor have I had anyone tried to come and confiscate my hardware, otherwise you would have seen me on the news. "HA!"
But as anyone who has dealt with government record keeping already knows, having registration type information in a government data base is probably the most private place to have it; unless it's used for collecting income tax they'll loose it.