The jury as a last resort against unfair laws can refuse to find the person guilty; there is no legal consequence to this. Prosecuters screen out people who know this so they follow the script.
Hell no, I'd vote to acquit the guy in a second.
From Wikipedia:
Jury nullification refers to a rendering of a not guilty verdict by a trial jury, disagreeing with the instructions by the judge concerning what is the law, or whether such law is applicable to the case, taking into account all of the evidence presented. Although a jury's refusal relates only to the particular case before it, if a pattern of such verdicts develops, it can have the practical effect of disabling the enforcement of that position on what is the law or how it should be applied. Juries are reluctant to render a verdict contrary to law, but a conflict may emerge between what judges and the public from whom juries are drawn hold the law to be. A succession of such verdicts may signal an unwillingness by the public to accept the law given them and may render it a "dead-letter" or bring about its repeal. The jury system was established because it was felt that a panel of citizens, drawn at random from the community, and serving for too short a time to be corrupted, would be more likely to render a just verdict than officials who may be unduly influenced. Jury nullification is a reminder that the right to trial by one's peers[1] affords the public an opportunity to take a dissenting view about the justness of a statute or official practices.
“ I consider trial by jury as the only anchor yet imagined by man by which a government can be held to the principles of its constitution. ”
—Thomas Jefferson, 1789 letter to Thomas Paine