The Treason Act 1381 (5 Ric.2 c.6) was an Act of the Parliament of England. It stipulated that "none from henceforth make nor begin any manner of riot and rumour, nor other like." To do so was made high treason. The Act was passed in response to the Peasants' Revolt earlier that year. It was repealed in 1399 by the Act of 1 Hen.4 c.10.
References
Treason Act 1381 Wikipedia(Text) CC BY-SA