"The BBC's director general George Entwistle has resigned over a chain of events culminating in a report on child abuse going out on Newsnight which led to Conservative peer Lord McAlpine being mistakenly implicated. In the wake of Mr Entwistle's resignation, further temporary changes have been made in order to "clarify" the chain of editorial command. Find out how the crisis at the BBC has developed." (Quoted from article)