A story in R. V. Jones’ “Most Secret War” fascinates me. Turned German agents were used to feed back false information about V1 impact points. The times given were correct but the locations were given as areas in NW London and Middlesex.
As a consequence, the Germans thought the missiles were overflying their targets in Central London and reduced the distance-to-fly in the propeller-driven odometer. This moved the average target location to the southeast and reduced overall damage and casualties. Tough if you lived in NW Kent though!