The UK government has defended using video-call service Zoom among senior government officials - including Boris Johnson - due to 'unprecedented circumstances' caused by the coronavirus.

On Monday, the firm's stock price climbed 22%. The firm is worth about $37 billion.

But cybersecurity experts have raised questions around Zoom's security and data privacy policies, with reports that the Ministry of Defence has banned staff from using it.

Boris Johnson used Zoom on Tuesday to hold his first remote Cabinet meeting, the private weekly meeting of the government's most senior ministers.

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The British government has defended the use of Zoom among senior officials, including Prime Minister Boris Johnson, citing the "unprecedented circumstances" presented by the coronavirus pandemic.

The video-call firm's stock price has shot up in recent days and it is currently valued at around $38.5 billion. The company has reported a spike in usage, as thousands of workers around the world work from home and use the service to talk to colleagues during lockdowns.

But cybersecurity and data privacy experts have raised concerns about Zoom's policies, citing recently discovered vulnerabilities and questionable in-app features.

Experts have queried how user data could be passed on to third parties such as Google, as well as an "employee tracker" feature that could allow a host to monitor whether an employee is paying attention.

The prime minister hosted his first "virtual Cabinet" meeting with senior government officials via Zoom on Tuesday. But that was just days after the Ministry of Defence reportedly banned staff from using it.

According to the Press Association, the MoD told staff to avoid communicating via Zoom while it investigated the programme's "security implications", reminding them to be "cautious about cyber resilience".

One source told PA: "It is astounding that thousands of MoD staff have been banned from using Zoom only to find a sensitive government meeting like that of the Prime Minister's Cabinet is being conducted over it."

According to a senior government source, however, who spoke to Business Insider on the condition of anonymity, there are apparently "no plans to pause or review" the MoD's use of Zoom for official business.

Zoom previously told Business Insider that issues highlighted by security researchers at Check Point, specifically a flaw that would allow hackers to join meetings, had been resolved before they were made public. The firm added that it had updated numerous features such as Meeting ID Validation and a Device Blocker meant to "limit the effectiveness of malicious tools."

The firm added that its in-app "employee tracker", which has been the source of some controversy, had been turned off by default.

Asked about the UK prime minister's use of Zoom, a government spokesman said: "In the current unprecedented circumstances, the need for effective channels of communication are vital.

"National Cyber Security Centre guidance shows there is no security reason for Zoom not to be used for conversations below a certain classification."

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