From the decision:

To summarize, we conclude that the Second Amendment
protects an individual right to keep and bear arms. That right
existed prior to the formation of the new government under the
Constitution and was premised on the private use of arms for
activities such as hunting and self-defense, the latter being
understood as resistance to either private lawlessness or the
depredations of a tyrannical government (or a threat from
abroad).

That's about as good as we could hope for!

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