Can they take them - Yes
Will they take them - No
In case of some wild deal that no one has come up with they may come knocking at you door. But since no one has thought that seneario up yet there is little possibility of it happening. I know someone will correct me but I don't know of any gun ban yet that the Fed have taken guns away, just not allowed to make any new ones. Even machine guns are still legal from a Fed standpoint. State or local is a different story.