We have a judiciary branch for this...
The jury system is not about whether a law is right or wrong. A prosecutor will often tell the jury that it is not up to them to decide a case based on whether they agree with a particular law.
Of course, the judiciary abuses its interpretation duties already. Giving similar powers to a bunch of schmoes off the street: not a good idea.
From the FIJA Website:
QUOTE
You can't be punished for following your conscience instead of the oath you take or the instructions you're given. What you and the other jurors decide to do behind closed doors is your business.
A QUICK QUIZ FOR PROSPECTIVE JURORSThis amounts to vigilantism, where any ONE juror can circumvent justice (since a unanimous jury decision is required in criminal cases...)