An error during standard maintenance on Facebook's network of data centers caused the global system to go down for more than six hours on Monday, causing a slew of issues that forced the repairs to be delayed, the firm said on Tuesday.
According to Downdetector, an online monitoring company, the outage was the largest it had ever seen. It restricted access to Facebook, Instagram, and WhatsApp apps for billions of users, heightening weeks of scrutiny for the almost $1 trillion business.

A former employee turned whistleblower accused Facebook of putting profits before of people's safety at a Senate hearing on Tuesday, which the firm denied.

Santosh Janardhan, Facebook Vice President of Engineering, stated in a blog post that the company's employees mistakenly separated Facebook data centers from the rest of the world.
According to Facebook, its systems are designed to audit commands to prevent errors, however the audit tool had a fault and failed to block the operation that triggered the outage.

It was also stated that the disruption was not caused by malicious activities.

Employees were also restricted from internal tools, while users lost access to one of the world's most popular messaging apps, WhatsApp, which has over 2 billion users.