The jury deliberates in secret. The jury returns a verdict. Judgement in a case depends on the jury returning a verdict. The jury can arrive at a verdict through any means they desire, including determining whether a law is valid or not, whether the facts fit the law, whether the facts are actually facts, or even flipping coins. As long as they all agree on the verdict and they deliberate in secret there is nothing that can be done about this.
Juries are the most powerful entities in our government, more powerful than the legislative, executive, and judicial branches combined. No person can be convicted, or even tried, for a felony, unless first indicted by a grand jury. On top of that, no person can be convicted of any crime, felony or misdemeanor, unless a jury returns a guilty verdict, excepting crimes where there is no trial, due to a guilty plea.
The fact that you don't seem to understand this simple concept is evidence that you've been hoodwinked. As P.T. Barnum was known for saying, "a sucker is born every minute". I was also suckered by this years ago (so I'm not really picking on you, just trying to wake you up), but I've spent some time reading up on the topic, and I've learned just how bad things really are, and have been for years now.