From Disloyal Opposition:
In Washington, D.C., a jury ignored a military veteran's obvious violation of the city's draconian gun laws, setting him free with only a slap on the wrist. In LaSalle County, Illinois, a medical marijuana user found with 25 pounds of the plant didn't even get the slap; jurors chatted with him after finding him not guilty. While we can't know for sure, in both cases jury nullification was likely at work as regular people serving an important role in courtrooms exercised their power to quash laws they found repugnant.
Corporal Melroy H. Cort, who lost his knees to an improvised bomb in Ramadi, Iraq, was en route to Walter Reed Hospital from his home in Columbus, Ohio, when his car got a flat. He and his wife, Samantha, pulled over for repairs, at which time Cort, who has a concealed carry permit at home, retrieved his 9mm pistol from his glove compartment and put it in his pocket....
Historically, as President John Adams put it, it has been the juror's "duty ... to find the verdict according to his own best understanding, judgment, and conscience, though in direct opposition to the direction of the court." Unfortunately, you won't come across that quote from Adams in many modern courtrooms. Government officials don't like being second-guessed by the hoi polloi, so the tradition of independent juries has been allowed to wither from neglect. Few jurors ever learn about the traditional power of juries.
But you don't need to know history to have an inkling that the rights of the individual sometimes violate the dictates of the law -- and then decide to come down in favor of individual rights. And individual rights are an endangered species in a nation increasingly hemmed in by laws and regulations that seem to render ever more of our daily activities either mandatory or forbidden. They need as much protection as they can get.
To preserve what's left of our liberty, jury nullification is a good and powerful tool for checking government power. But since it is frequently discouraged by judges and prosecutors jealous of their prerogatives, it's generally exercised on the sly -- often by jurors unaware that they're doing exactly what was originally intended. For that reason, we'll likely never know exactly when nullification is being exercised.
But we can celebrate it when we see it.