Thousands of Google staff are protesting against the use of the company’s technology in the Pentagon’s controversial drones programme.

The US Department of Defense's Project Maven, commenced last April, utilises the Silicon Valley search giant's artificial intelligence system to analyse vast amounts of footage captured by the US Army’s unmanned surveillance planes around the world.

Around 3,100 staff are thought to have signed a letter to Google boss Sundar Pichai, demanding that the company pulls out of the project.

Google confirmed last month that the Pentagon was using its technology, sparking outrage among some of its employees.

A copy of the letter published in the New York Times said: “We believe that Google should not be in the business of war.

“Therefore we ask that Project Maven be cancelled, and that Google draft, publicise and enforce a clear policy stating that neither Google nor its contractors will ever build warfare technology.”

The letter refers to Google’s TensorFlow technology, an open-source machine learning system which is being used by the Pentagon on a pilot project

Why are Google staff protesting?

The US drone programme captures vast amounts of surveillance from around the world, some of which is used as intelligence to establish targets for airstrikes.

There have been tens of thousands of strikes in Iraq and Syria by coalition forces since the US-led intervention began in 2014.

In December, the task force co-ordinating military action against Isis in the region said 814 civilians had been “unintentionally killed” and that nearly 700 reports of possible casualties remained open.

The letter states that participating in the drone programme is “risky” for Google and the fact that Amazon and Microsoft are also involved does not make it any less so.

“Google’s unique history, its motto Don’t Be Evil, and its direct reach into the lives of billions of users set it apart,” the letter states.

“We cannot outsource the moral responsibility of our technologies to third parties.

How exactly is Google involved in the drone programme?

Google, along with some other technology firms, has provided support for Project Maven, which aims to automate the analysis of US drone footage as the amount of video captured has become increasingly unmanageable for human processing.

TensorFlow has been used to identify objects that may be of interest. These are then passed on to human beings who assess the images Google’s system has highlighted.

How has Google responded to the protest?

The company issued a statement saying that it had “long worked with government agencies to provide technology solutions”.

A spokesperson added: “The technology flags images for human review, and is for non-offensive uses only. Military use of machine learning naturally raises valid concerns.