A bit more background on Henry David Thoreau: he protested the poll tax and American participation in the Mexican War. For the poll tax violation, the sheriff put him in jail for a brief time. Henry never found out who, but either his mother or his aunt payed the poll tax. When the sheriff came to release him, Thoreau argued that since he didn't pay the poll tax himself he was still not in compliance with the law and he had a right to stay in jail.
The sheriff, who understood that Thoreau was an endearing crank but no threat to society, had been forced to lock him up for breaking the law, but he knew as well he didn't belong there. When Thoreau tried to refuse to leave, reasoning with the sheriff that since he didn't pay the tax himself he had a right to stay, the sheriff, out of patience with him, said, "Henry, if you don't get out of my jail, I'll throw you out."(This information comes from an old introduction to Thoreau's essays from a book I no longer have and therefore I can't offer an accurate citation.)
I accept that non-compliance with gun laws in places of heavy restriction is significant and probably very high, but I question how much good it does our side when a writer throws out percentages he doesn't support.
Also, as AlexanderA points out above, unless he defiance is open and public it's not Civil Disobedience. You might want to carefully consider when and where you engage in Civil Disobedience. As an example, I believe I have a perfect Constitutional right to strap on my six-gun openly, walk into a New Jersey police station and announce what I believe is my right. Given that New Jersey's gun laws are passed by their legislature by popularly elected representatives of the state, such an act would end badly for me, accomplish nothing, and I think it's fair to assume that the majority of the people of that state would applaud my fate.