Yosef Karo, Shulchan Aruch — Choshen Mishpat 4
“ But in the case of an individual in conflict with an entire community, the law is that if he is one of the townspeople they may take the law into their own hands in order to safeguard their interests, provided if they know that the law is in their favor, although they are unable to prove this before the Court of Law, — for they cannot testify since they are all interested parties in the matter. ”
