2006 Idomeneo controversy
On 26 September 2006 the Deutsche Oper Berlin announced the cancellation of four performances of Mozart's opera Idomeneo, re di Creta, planned for November 2006, citing concerns that the production's depictions of the severed head of the Islamic prophet Muhammad raised an "incalculable security risk". "To avoid endangering its audience and employees, the management has decided against repeating Idomeneo in November 2006", the opera house said in a press release.
Source: Wikipedia — 2006 Idomeneo controversy (CC BY-SA 4.0)