“The Met’s latest poster campaign urges Londoners who spot “unusual” activity to ring the police and let them know. Examples include someone taking pictures of CCTV cameras or acting out of the ordinary. After all, these are dangerous times, and we all must be vigilant.”

“Contrast this for a moment with an earlier dangerous time: the Blitz. Bombs rained down upon London on a near-daily basis, killing, maiming and laying waste to whole neighbourhoods (one American friend recently described a trip around east London where his hosts pointed to every car park and said, “Of course, that was bombed in the Blitz” – and came away with the impression that Hitler had dropped car parks on Hackney).”