Jury Nullification

A most interesting right: Jury Nullification, the right of the jury to vote their conscience and veto the law they consider unjust.

After all, why do we have jury and jury duty in the first place if everything could be decided by the judge? That the judge would tell the jury to judge the defendent merely by the facts, and not to judge the law is an indefensible and unconstitutional abrogation of the rights of jury. The right of the jury is not exactly denied to them, it is not told to them either.

Wikipedia

If you get summoned for jury duty, remember that, if you can get 11 other people to agree with you, you have the power to veto a law you believe is unjust by clearing a defendant of his or her crime, such as medical marijuana.