After months of concern over interference in the media by the intelligence services, the BBC has invited the former head of the security service MI5 to be guest editor of the Today programme.
But Eliza Manningham Buller will use the one-day editorial opportunity to investigate the use of an espionage tool associated with a less technological age - the pigeon. The former MI5 director general will also examine the subject of urban design with architect and designer Thomas Heatherwick.
As part of Today's annual experiment with guest editors, the inventor of the World Wide Web Sir Tim Berners Lee will also take the helm at the programme for a single day. He will examine future threats to a free and open web, asking listeners to contribute views on what they want from the Internet in future.
This year's other guest editors are the musician PJ Harvey, Michael Palin and the group chief executive of Barclays Antony Jenkins.