Affair of the Placards led to several people being burned at the stake

The Affair of the Placards (French: Affaire des Placards) was an incident in which anti-Catholic posters appeared in public places in Paris and in four major provincial cities: Blois, Rouen, Tours and Orléans, overnight during 17 October 1534. One was actually posted on the bedchamber door of King Francis I at Amboise, an affront and an alarming breach of security that left him shaken. The Affaire des Placards brought an end to the conciliatory policies of Francis, who had formerly attempted to protect the Protestants from the more extreme measures of the Parlement de Paris, and also of the public entreaties for moderation of Philip Melanchthon.

• http://en.wikipedia.org/wiki/Affair of the Placards