At the May 31 matinee of The History Boys, American theatergoers got their first taste of what may be the most practiced cellphone rebuke in show business. During a critical scene in which Griffiths' character, Hector, is being taken to task by the Headmaster (played by Clive Merrison), several phones rang and the actor stopped the show. "I can't compete with these electronic devices," he said, according to the New York Times. "Now you were asked nicely by the stage manager [to turn them off]. You were told that it's against the law." He then said he would start the scene again and, if interrupted once more, wouldn't continue. "You've been warned," he admonished. When the scene began anew, responding to the Headmaster's inquiry about why he locked the classroom door during lessons, Griffiths uttered the scripted line, "I don't want to be interrupted." The audience reportedly laughed and burst into applause.

According to the New York Post, the erupting phones came from the same row and were all owned by different members of the same family.

In England, Griffiths once successfully ejected a women from a theatre after her cellphone rang.