What was going on in that Homeland scene when things went a bit Black Mirror?

As Conlin discovers, whoever is behind the explosion is connected to a nameless, ominous corporation, based in a building that runs at least six floors deep underground. The offices are teeming with ex-spooks looking to cash in and get their mitts on masses of data that were previously off-limits. Or as the amiable man from an NSA top hacking team puts it to Conlin: “We’re a node on the parallel backbone, sitting on the biggest fibre optic cable transit in the world… 96.8 per cent of the world’s data.”

It may seem like a scene from Black Mirror – something that hasn't yet come to pass – but the idea of a private intelligence agency is actually a nod to the booming “spies for hire” industry in America…

How does the private intelligence industry work in the US?

Historically, the US government has gathered its data in-house, through the Central Intelligence Agency (CIA) and the National Security Agency (NSA). However, a shift in strategy as part of the War on Terror has led to a surge in out-sourcing intelligence gathering to private companies.

Increasingly, therefore, it is private contractors who are trawling through data, messages, phone calls and documents. As depicted in Homeland, most of them will have spent many years working in intelligence in the public sector – including for agencies like the CIA, but also military or police operations – before transferring to the private sector to earn serious dollar.

According to a 2013 New York Times article, seventy per cent of America’s intelligence budget is allocated to private agencies, making private intelligence a $56 billion-a-year industry.

One such American agency is Booz Allen Hamilton, where Edward Snowden was a contractor before becoming responsible for the biggest leak in the history of the NSA.

Contract spying is a source of much controversy, as the involvement of such huge sums of money can lead to corruption and seriously threaten privacy and democracy.

Is private intelligence just as booming here in the UK?

Not to the same extent as in the US, but the big private intelligence firms in the UK include Alaco, Control Risks and GPW.

We did have a recent Snowden-esque affair whereby Christopher Steele, a former MI6 spy, famously compiled the “dirty dossier” on Donald Trump. The dossier claimed that Trump associates colluded with the Kremlin’s cyberattacks on Democrats, and that Russian spies held compromising information on the Republican candidate – including proof of prostitutes urinating on him in a Russian hotel (something which the president denies).

Steele is a classic example of an ex-government “spy for hire” who founded his own intelligence company, Orbis, upon leaving MI6. Steele has been in hiding ever since details of the dossier emerged – in a scandal that wouldn’t look amiss as a storyline in a political thriller, come to think of it…