The Guns Case Is About Much More Than Guns

New York City and State have allowed them to do that, two times over.
In this case, the plaintiffs sought only injunctive and declaratory relief—that is, a prohibition to ensure that New York City would stop enforcing its law.
Given that the case is transparently moot, the plaintiffs are relying on an exception known as the “voluntary cessation” rule.
The rule allows a court to decide a case that has become moot because a defendant voluntarily ceased its conduct.
That’s not a risk here, because New York City and New York State would both have to change their laws again to prevent the plaintiffs from transporting their handguns.