In pictures: The Writers Guild of America strikes

New York City, USA: The WGA picket line outside the Rockefeller Centre, headquarters of NBC Photograph: Stan Honda/AFP

New York City, USA: The entrance to NBC studios seen through picket signs Photograph: Justin Lane/EPA

New York City, USA: Tina Fey, creator and star of NBC show 30 Rock, joins a picket line outside the Rockefeller Centre Photograph: Justin Lane/EPA

Los Angeles, USA: James L Brooks, writer for and producer of The Simpsons, joins the picket outside Fox studios Photograph: Gabriel Bouys/AFP

Culver City, USA: WGA members gather outside the offices of Sony Pictures Entertainment Photograph: Gabriel Bouys/AFP

Culver City, USA: Picketers with placards outside the Sony Pictures Entertainment studio Photograph: Gabriel Bouys/AFP

New York City, USA: Musicians play in support of the WGA picket line Photograph: Mario Tama/Getty

Los Angeles, USA: The WGA picket outside CBS's Radford studios Photograph: David McNew/Getty

Burbank, USA: The picket line outside Warner Brothers studios Photograph: Gus Ruelas/AP

Los Angeles, USA: A striking member of the WGA wears a T-shirt stating 'Unfair is Unfunny" on the picket line outside Warner Brothers studios Photograph: David McNew/Getty