https://en.wikipedia.org/wiki/Jury_nullification

 

Jury nullification is a concept where members of a trial jury can vote a defendant not guilty if they do not support a government's law, do not believe it is constitutional or humane, or do not support a possible punishment for breaking a government's law. This may happen in both civil and criminal trials. In a criminal trial, a jury nullifies by acquitting a defendant, even though the members of the jury may believe that the defendant did the act the government considers illegal. This may occur when members of the jury disagree with the law the defendant has been charged with breaking, or believe that the law should not be applied in that particular case. A jury can similarly convict a defendant on the ground of disagreement with an existing law, even if no law is broken (although in jurisdictions with double jeopardy rules, a conviction can be overturned on appeal, but an acquittal cannot).

There are times when it is appropriate for a jury effectively to say "up yours" to the prosecution It happened in 1980-something when a civil servant (Clive Ponting) was charged with leaking documents to the press. There was no doubt that he had done it, but the jury acquitted him. The same logic applies if a punishment is seen as excessive. A jury would be perfectly justified, for example, in acquitting somebody accused of nicking twenty quid from a till if the likely penalty was 15 years in prison.

There are times when it is appropriate for a jury effectively to say "up yours" to the prosecution It happened in 1980-something when a civil servant (Clive Ponting) was charged with leaking documents to the press. There was no doubt that he had done it, but the jury acquitted him. The same logic applies if a punishment is seen as excessive. A jury would be perfectly justified, for example, in acquitting somebody accused of nicking twenty quid from a till if the likely penalty was 15 years in prison.

 

I wish I'd been on Tony Martin's jury...