ISRAEL’S military intelligence agency, Unit 8200, has been using Microsoft’s European cloud infrastructure to store and analyse a vast archive of intercepted Palestinian phone calls, enabling mass surveillance of civilian life across Gaza and the occupied West Bank.
The system, described by Israeli officers as capturing ‘a million calls an hour’, has directly supported airstrikes and detentions, and remains central to the regime’s pursuit of ‘long-term control’ over the Palestinian population.
The revelations come from a joint investigation by the Guardian, +972 Magazine, and Local Call, which drew on leaked internal Microsoft documents and interviews with sources inside Unit 8200 and Microsoft.
Since 2022, Israeli intelligence has stored thousands of terabytes of raw audio surveillance on Microsoft’s Azure servers in the Netherlands and Ireland, bypassing domestic infrastructure limits and creating an unprecedented digital dragnet over Palestinian communications.
Unit 8200’s data storage needs grew dramatically after its leadership, under commander Yossi Sariel, embraced a shift from traditional target-based surveillance to population-wide monitoring.
This pivot, developed after a series of deadly attacks by young Palestinians, many of whom were previously unknown to intelligence services, led Sariel to pursue AI-enabled tools that could ‘track everyone, all the time’.
The result was a cloud-based system designed to retain and retrospectively analyse the private conversations of millions of civilians.
In late 2021, Sariel travelled to Microsoft’s headquarters near Seattle to pitch the cloud migration plan directly to CEO Satya Nadella.
According to internal Microsoft records seen by the media investigation, Nadella expressed support for the proposal, suggesting the company identify ‘certain workloads to begin with’ and later scale up to migrate as much as 70% of Unit 8200’s classified data to Azure.
He reportedly called the partnership ‘critical’ and pledged resources to support the unit’s ambitions.
Microsoft now denies that Nadella was aware of the nature of the data being transferred.
Following this meeting, Microsoft engineers in Israel and abroad collaborated with Unit 8200 to build bespoke security measures around the system.
One internal document described daily collaboration between Microsoft staff and military officers, including Unit 8200 veterans now employed by the tech giant.
Engineers were instructed not to name the unit in official materials, and senior staff were aware that the stored data consisted of raw audio files.
‘You don’t have to be a genius to figure it out,’ one source said.
‘You tell them it’s audio files and you’ve run out of space – it’s obvious.’
By mid-2025, more than 11,500 terabytes – roughly 200 million hours of recordings – had been stored on Microsoft’s European servers, with Unit 8200 planning to migrate even more of its archives, including top secret material.
Intelligence officers confirmed that intercepted calls were used to select bombing targets in Gaza, often by reviewing conversations made near recent airstrikes.
In other cases, calls stored in the cloud were reportedly used to justify arrests or killings where no immediate grounds existed.
‘When they need to arrest someone and there isn’t a good enough reason to do so,’ one source said, ‘that’s where they find the excuse.’
Microsoft claims to have ‘no information’ about the content of the data stored by Unit 8200.
The company stated that its engagement with the unit focused on cybersecurity and defence against cyber-attacks, and that it has not knowingly supported surveillance of civilians or the targeting of individuals.
However, internal records and interviews indicate that Microsoft staff were aware of the project’s purpose, with one employee describing the company’s role as providing ‘infinite storage’ for intelligence operations in Palestine.
In addition to data storage, Microsoft also provided AI technologies to assist Israeli intelligence efforts.
Among them was a tool known as ‘noisy message’, which scans text messages and assigns a risk rating to conversations containing words deemed suspicious, such as references to weapons or death.
Though originally used to monitor the West Bank, this tool and others developed under Sariel’s leadership have been widely deployed during Israel’s ongoing military campaign in Gaza, which has killed over 60,000 people, the majority civilians, including more than 18,000 children.
Sariel, known within military circles as a ‘tech evangelist’, prioritised the cloud partnership as a strategic solution to Israel’s intelligence limitations in the Palestinian territories.
He reportedly framed the collaboration with Microsoft as the answer to Israel’s ‘problems in the Palestinian arena’, securing substantial budgets to implement the transition.
He later resigned in the aftermath of the October 2023 Hamas-led resistance operation, which killed nearly 1,200 Israelis and saw hundreds taken captive – an event widely perceived within Israel as a catastrophic intelligence failure.
Sariel took public responsibility for Unit 8200’s failure to anticipate the operation, which occurred despite the unprecedented levels of surveillance enabled by the Azure system.
Nonetheless, the cloud-based system has remained active throughout the genocidal assault on Gaza that followed.
Even as Israel’s military systematically destroyed Gaza’s telecommunications infrastructure, officers continued to rely on previously stored calls to assist in targeting and operations.
Sources close to Unit 8200 reported growing enthusiasm for the system’s potential to support long-term occupation and control over the territory, describing it as a foundational tool in the regime’s efforts to maintain dominance through technological superiority.
Some within Microsoft reportedly viewed the partnership not just as a matter of strategy, but also as a major business opportunity. Internal documents suggested the collaboration with Israeli military intelligence could yield ‘hundreds of millions of dollars’ in revenue and serve as a landmark moment for the Azure brand in the global cloud market.
‘(Unit 8200’s) leadership hopes to expand the mission-critical work tenfold in the coming years,’ one executive noted.
Another described the project as a ‘revolution’ in surveillance and cloud integration.
Although Microsoft insists its services must not be used to identify targets for lethal strikes, Unit 8200 insiders say this stipulation has been ignored.
Call metadata and recordings stored on Azure were directly used to research targets for bombings in densely populated civilian areas of Gaza.
In some cases, officers would review recent call activity around a target zone to retroactively justify an airstrike.
One officer explained that the purpose of storing such massive volumes of data was precisely to make these retroactive justifications possible.
The media investigation also uncovered claims that information held in the cloud has been used to blackmail Palestinians, detain individuals without evidence, or conduct killings justified after the fact.
A former officer described the logic of the system bluntly: ‘Suddenly the entire public was our enemy.’
The AI-powered dragnet, originally justified as a tool for national security, now functions as an all-encompassing apparatus of population control, operating with the assistance of a major US technology corporation.
In response to rising internal dissent, Microsoft commissioned an external review of its relationship with Israeli defence entities.
The review claimed to have found ‘no evidence’ that its products were used to ‘harm people’ in Gaza.
Yet engineers continue to report internal disquiet with the company’s complicity.
One employee reportedly interrupted a keynote speech by Nadella in May, shouting: ‘How about you show how Israeli war crimes are powered by Azure?’
Despite official denials, the evidence suggests Microsoft’s partnership with the Israeli military has gone far beyond neutral service provision.