The 14th century open-air fresco depicting Il Cristo di Piet in Piazza Ara Coeli has been vandalized by excrement thrown from the street. The department of arts and heritage was alerted on 12 November but, according to superintendent Eugenio La Rocca, cleaning was delayed until restorers could establish the nature of the substance thrown against the fresco and attain city permits to mount the scaffolding necessary to remove it. Cleaning and restoration is scheduled for the last week of November.

Il Cristo di Piet is one of the few remaining works to be seen of the late 14th century church S. Biagio del Mercato, which was built atop the 2nd century Insula Romana and demolished in 1929 in order to clear the way for todays Via del Teatro Marcello.