Coba jelasin Masalah keamanan dari Joker (film 2019) dong

Pada 18 September 2019, the United States Army distributed an email warning service members of potential violence at theaters screening the film and noting the Joker character's popularity among the incel community. A separate memo revealed the Army received "credible" information from Texas law enforcement "regarding the targeting of an unknown movie theater during the release." However, according to Deadline Hollywood, the FBI and the United States Department of Homeland Security found no credible threats surrounding the release of the film.

Dalam sebuah wawancara dengan TheWrap, Todd menyatakan keterkejutannya dalam serangan balasan ini, stating he thought "it's because outrage is a commodity" and calling critics of the film "far-left". Phoenix walked out of an interview by The Telegraph when asked if the film could inspire mass shooters. He later returned to finish the interview, but did not answer the question. Following this, journalists were disinvited from the premiere at TCL Chinese Theatre, with only photographers being allowed to interact with the filmmakers and cast on the carpet. In a statement to Variety, Warner Bros. said that "A lot has been said about Joker, and we just feel it's time for people to see the film."

Film ini tidak ditayangkan di bioskop di Aurora, Colorado tempat penembakan massal yang terjadi pada 2012 ketika penayangan The Dark Knight Rises. Tiga keluarga korban, serta ibu seorang saksi, menandatangani sebuah surat yang ditujukan kepada Warner Bros. untuk tidak menayangkan film ini di bioskop di kota itu. Additionally, Landmark Theaters has prohibited moviegoers from wearing Joker costumes during its run, while the Los Angeles and New York City Police Departments increased police visibility at area theaters, though they did not receive "any specific threat."