WikiLeaks revelations about CIA surveillance operations threw into the public domain another set of odd-sounding codenames. The surveillance programme that caught the most attention, about how agents can make a television look as if it is off while in fact it is recording conversations, is known as Weeping Angel.

The WikiLeaks trove also gives us Brutal Kangaroo, Fine Dining, HammerDrill and HarpyEagle.

It has been suggested that Weeping Angel was inspired by the humanoids in Doctor Who. It might seem like an odd choice by American intelligence officials, but the Time Lord is well known in the US, where the programme long ago achieved cult status. Britain’s intelligence agency MI5 collaborated with the CIA on developing the snooping programme, so the inspiration could equally well have come from the UK side.

Both the US and British intelligence agencies insist that codenames are not selected on the basis of the personal whims of those involved. Instead, they say, they are randomly chosen by computer. But these names are often taken from popular culture.

In the age before computers, the intelligence services insisted that codenames were decided at random. Nevertheless, codenames given to MI6 and MI5 agents in the 30s and 40s frequently reflected the personality traits of those agents.

During the second world war, the Germans used codenames that offered a hint of what a secret operation was about, but the Americans and British used random lists of words, though politicians, the military and intelligence officers involved were allowed to select from such lists. Why were they allowed a choice? One later US military operation, the US intervention in Panama in 1989, was originally codenamed Blue Spoon but, after deciding it would be hard to boast about having fought in Blue Spoon, the military quickly renamed it Just Cause.

The mass leak by Edward Snowden of the National Security Agency surveillance programmes provided hundreds of codenames, again seemingly chosen at random: Bullrun, Boundless Informant, Prism, Tempora, Royal Concierge, the Three Smurfs, and so on. There seems no obvious connection to the programmes involved, although the inclusion of the Three Smurfs is further evidence that the agencies are happy to borrow from popular culture. Of the Three Smurfs, Dreamy Smurf was aimed at turning on smart phones, Nosey Smurf at turning on a phone’s mic, and Tracker Smurf at monitoring personal information, including locations.

Tempora, the programme developed by the UK’s GCHQ to tap into fibre-optic cables carrying internet traffic, could have been lifted from Cicero’s quote “O tempora o mores” (“Oh, what times. Oh, what customs”). Royal Concierge was a system used for tracking hotel bookings.

The US security service offers incoming presidents a list of codenames that are again randomly chosen. Reagan went for Rawhide, a reference to a popular television western. Obama went for Renegade. Trump has plumped for Mogul.