Nothing justifies snipers pointing their rifles at peaceful protestors. Ever.
An armed man is a citizen, a disarmed man is a slave. Blacks Codes since the 1600's have kept blacks disarmed. The entirety of the Dred Scot decision was based on "granting Mr Scot citizenship would confer upon the Right to Bear Arms."
Peace through Strength is why white communities aren't terrorized on a daily basis by the police, the Battle of Athens, Tennessee, 1946 proved that whites will use armed force and overthrew oppressive police forces.
The black man was a slave in the past, is a slave today, and so long as he is disarmed, will forever be a slave.
Assert your rights, and arm yourselves. Once you're armed, you'll never have to use your firearms, tyrants are bullies, too cowardly to ever consider provoking an armed population.
There is only one logical practice of the Second Amendment, and that is that it shall not be infringed. Any other practice is an absurdity, for it contradicts the very purpose of the Second Amendment in its entirety; it is the ultimate form of popular recourse against tyranny, and thus no potential tyrants may restrict it. To surrender the Second Amendment is to surrender the sovereignty of self-government.