The National Coalition Against Censorship, the National Opera Association, Article 19, The Dramatists Legal Defense Fund, Free Expression Policy Project, freeDimensional, Freemuse, and PEN American Center have issued a statement opposing the Metropolitan Opera's cancellation of live HD simulcast of John Adams' opera, The Death of Klinghoffer, to about 2000 cinemas in 65 countries. They are urging the Met and its director, Peter Gelb, to reconsider that decision. According to Broadway World, further organisations are expected to join the protest.
Ole Reitov, director of Freemuse, has commented (as quoted on Broadway World): "Whether self-censoring is motivated by pressure from corporate, social or political interests, cultural institutions should never forget, that once they accept such pressure they lose artistic credibility and signal lack of integrity."
The full statement from the NCAC is online here, but my computer is refusing to load it. I hope this is due to weight of traffic, and does not suggest some sort of online censorship of anti-censorship.
UPDATE, 22 June, 10.20am: If you only read one piece on this subject, make it this one, from a British-Israeli tenor who has sung in the opera: