Spies and saboteurs have long been part of warfare, but have you ever considered your meddling colleague may be using the same tried-and-true tactics?

In 2008, the US Central Intelligence Agency made public a World War Two-era handbook written for grassroots sabotage.

Titled the Simple Sabotage Field Manual, the aim of the handbook was to help citizens in occupied Allied countries bring down their governments from within – whether it was meddling with a military car on the streets in the dead of night, or casually lighting a warehouse on fire.