Guys handguns aren't just protected by the constitution for lawful purposes. They are also authorized for use against the government when the government becomes tyrannical.
So for instance if some pig came after me for driving my M5 at the kind of speeds it is engineered for, or if the IRS came after me with an unreasonable tax increase, I could take arms and overthrow the US government for that kind of tyranny. In fact it was done once before in the case of a tax increase - see 1776!
I wonder at what level of tax increase would we be justified to shoot the government.
2014 Porsche 911 Turbo S
2015 Mercedes-Benz C300 Sport 4MATIC