Ever since the first federal laws prohibited convicted felons from owning firearms was written, the federal and state laws concerning guns proliferated. Now we are facing outright bans on certain types of arms and not only by our own government, but also from the international body of the United Nations.
I for one find the laws are all unconstitutional and therefore null and void. The Constitution is explicit. The Second Amendment as it is written states:
A well regulated militia, being necessary to the security of a free state, the right of the people to keep and bear arms, shall not be infringed.
It does not make any provisions for government to infringe on the rights of the People based on their social standing, criminal history, or the types of weapons they may possess. It was meant as a protection of the people from a tyrannical government or other enemies of the people. Now the first part of the amendment has been taken to mean a state's guardsmen, which is in fact incorrect.
Militias were local citizens who banded together to form their own protective guards. It does allow for the governors of states to call up the militias of the various communities and to assign or conscript them to serve under the President as Commander-in-Chief during times of war. Later laws such as the War Powers Act, shredded the explicit limitations placed on both the State and the Federal governments by the Constitution by allowing standing armies during peacetime and by virtually eliminating the militias by the creation of the National Guards, a federally mandated army under the authority of the State Governor but in actual practice the President of the United States.
Any law that limits the organization of citizen armies (militias) or limits the right of the People to "keep and bear arms" is by virtue of the Constitution, null and void. It is not the government that needs to protect these rights when it it clear that the government is disobeying the limits place upon it by the People.
It is the duty of the People to protect their own rights by resistance to laws that clearly violate their rights. There are groups today who are exercising those rights much to the opposition of the federal government. (See: The truth behind America's 'civilian militias')
Freedom Outpost: All Federal Gun Laws Are Unconstitutional