The bocche di leone (lion’s mouths) appeared in Venice after 1310, when the Republic crushed the conspiracy of Bajamonte Tiepolo and decided to give itself eyes everywhere. They were Istrian-stone containers walled up at strategic points of the city, with a slit into which anyone could slip a sheet bearing an accusation. No signature was needed, but an anonymous accusation that was not detailed enough risked being discarded by the magistrates.