In an airconditioned shipping container plonked in the Nevada desert, a tense soldier's hand quivers on a joystick.

On the other side of the globe, an armed drone hovers above a suspected suicide bomber's home, poised and ready to fire its missiles.

Elsewhere, superior officers lean back in plush leather armchairs - watching the drama unfold through widescreen TVs - prepared to sign off the attack.

These are, of course, scenes from an intense Hollywood blockbuster, Eye in the Sky, starring Aaron Paul, Helen Mirren and the late Alan Rickman.

There's a bellowing soundtrack heightening every moment. There are extreme close-ups of Aaron Paul's sweat. There's Alan Rickman looking pissed off about ninety minutes straight.

It's fiction.

But former US drone technicians-turned-whistleblowers Lisa Ling and Cian Westmoreland say that approach to armed drone warfare isn't too from front-line reality.

Ling and Westmoreland both spoke out about US military tactics for Sonia Kennebeck's documentary, National Bird, showing this month at the Melbourne International Film Festival.

Lisa Ling says drone warfare used by the US military to fight terrorism in the Middle East is counterproductive.

"Say you're an 11-year-old child gardening with your grandmother," Lisa Ling told Hack, "One minute you're gardening and the next minute you turn around and see your grandmother in pieces.

"When that person gets to be a little bit older, that's the only part of the Western world that this child has seen.

"It's not like we've gone there and talked to them and shown them good will, the only part of the Western world that these people see is a drone.

"To have that loitering and not knowing if somebody in the next few moments is going to die - somebody you care about, you, whatever.

That, in my world view, is called terrorism."

How armed drones work

The United States' armed drone program is extremely secretive.

Hack asks Lisa how military drones identify targets and collect intelligence.

"Some of it I cannot tell you," Lisa says.

"Basically what you're looking at is like a big vacuum cleaner that flies over and sucks up endless amounts of information. Cell phone data, metadata. In fact, basically that's what is used - metadata is used to kill people.

"Say they're on Facebook, say they're on Twitter - all of that goes into making a profile of the individual.

"That alone compared with say, imagery intelligence, would be enough to make a strike. The issue with it, there's no in-depth knowledge of the individual, you just know that their metadata has the same patterns as a key individual or a terrorist."

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It's partly because of this strategy that Cian and Lisa spoke out.

Cian was one of the US Air Force communications experts who built a critical component of the global communications infrastructure underlying the drone program. He does not feature in the film.

"It's a symptom of cultural arrogance to go in there and think we can actually determine who is a good guy or a bad guy based on stuff we see on a screen," Cian says.

Once a target has been identified, the amount of people involved in executing a strike is so vast, it becomes difficult for individual technicians to understand exactly what they're doing, Lisa and Cian say.

"When it comes to killing an individual [in the drone program], there are so many people involved in the decision-making process that it's really hard to grapple with while you're in it.

Lisa says that kind of detachment reflects the famous Yale study into human obedience, the Milgram experiment.

"Basically [the Milgram experiment looks at] the distance between a human being and the person who is inflicting pain or death on a human being.

"And having pressure to do this, the further away you are from the human being, the easier it becomes to inflict pain up until the point of death.

"The other thing is authority. If you have an authority there telling you to do it, which you do when you're in the drone program, then the responsibility is somewhat taken off your shoulders. It's not necessarily your decision, it's the decision for the US air force."

Secrecy and 'near certainty'

According to Cian, part of the issue with armed drone strikes is the lack of public knowledge on who the victims are, and accountability when it comes to civilian deaths.

"You don't actually know who these victims are. We have evidence to say that they are terrorists, but they don't know. And nobody tells the public what evidence it is they have. It's a secretive thing."

Earlier this month, the White House released figures on how many "non-combatants" were killed by drone strikes in Pakistan, Yemen, Somalia and Libya between January 2009 and the end of 2015.

They put the number between 64 and 116.

But those figures have been criticised by the Bureau of Investigative Journalists, who believe the figure to be at least six times higher - as determined "from reports by local and international journalists, NGO investigators, leaked government documents, court papers and the result of field investigations."

In 2013, US President Barack Obama defended his Government's use of armed drones. He said drone strikes were only carried out when there was "near certainty" that the target was present.

"We're talking about life and death," Lisa says. "Is 'near certainty' good enough?"