mob law

"With mills and mill-hands," her ladyship announced to Mr. Laurence, the mill-owner, when chance first threw them together, "with mills and mill-hands come murder, massacre, and mob law."

From A Fair Barbarian by Frances Hodgson Burnett

I think I said something about mob law.

From Report of the Proceedings at the Examination of Charles G. Davis, Esq., on the Charge of Aiding and Abetting in the Rescue of a Fugitive Slave Held in Boston, in February, 1851. by Various

The duel is a relic of barbarism and should be no longer tolerated; it is mob law, really, and indefensible, with two persons defying the statutes instead of a thousand.

From Kennedy Square by Francis Hopkinson Smith

What we call nowadays mob law had not yet made its appearance—that is, in connection with witchcraft.

From A History of Witchcraft in England from 1558 to 1718 by Wallace Notestein

"It's mob law," said the Lieutenant, indignantly, "and I won't stand for it."

From The Barrier by Rex Ellingwood Beach