To quote the Magna Carta of 1215:

Quote Originally Posted by Magna Carta
20) For a trivial offence, a free man shall be fined only in proportion to the degree of his offence, and for a serious offence correspondingly, but not so heavily as to deprive him of his livelihood. In the same way, a merchant shall be spared his merchandise, and a husbandman the implements of his husbandry, if they fall upon the mercy of a royal court. None of these fines shall be imposed except by the assessment on oath of reputable men of the neighbourhood.

(21) Earls and barons shall be fined only by their equals, and in proportion to the gravity of their offence.
So punishing someone who has done nothing wrong, had been forbidden under British law for nearly 800 years. Plus the Magna Carta
is part of the base of American law since it is so old.