“We interrupt this programme…”, has become a television cliché in both fact and fiction. The fight for the television transmitter is key in many attempted coup d’états.

Formal interruptions sanctioned by the networks are reserved for the gravest occasions. In recent weeks each of the original networks in the US — CBS, NBC and ABC — have interrupted normal programming to cover Joe Biden’s statements on the attack on Ukraine.

Walter Cronkite and Dan Rather reporting the assassination of JFK have become legendary entries in the annals of live TV. The turbulence and progressive currents of the 1960s were also apparent in the decision of NBC in 1965 to break into its Sunday night movie Judgment at Nuremberg to broadcast fresh footage of the brutal suppression of the civil rights march at Pettus Bridge, Selma, Alabama.