Facebook, Whatsapp, Instagram back after nearly 6-hour outage

Facebook, Instagram, Messenger and WhatsApp lit up again early Tuesday after a nearly six-hour outage that prevented the company’s 3.5 billion users from accessing its social media and messaging services.

Facebook apologized but did not immediately explain what caused the failure, the largest ever tracked by web monitoring group Downdetector.

The outage was the second blow to the social media giant in as many days after a whistleblower on Sunday accused the company of repeatedly prioritizing profit over clamping down on hate speech and misinformation.

As the world flocked to competing apps such as Twitter and TikTok, shares of Facebook fell 4.9 percent, their biggest daily drop since last November, amid a broader selloff in technology stocks on Monday. Shares rose about half a percent in after-hours trade following the resumption of service.

“To every small and large business, family, and the individual who depends on us, I’m sorry,” Facebook Chief Technology Officer Mike Schroepfer tweeted, adding that it may take some time to get to 100 percent.

Several Facebook employees who declined to be named said that they believed that the outage was caused by an internal mistake in how internet traffic is routed to its systems. The failures of internal communication tools and other resources that depend on that same network in order to work compounded the error, the employees said.

Security experts said an inadvertent mistake or sabotage by an insider were both plausible.

Twitter on Monday reported higher-than-normal usage, which led to some issues in people accessing posts and direct messages.

Facebook, which is the world’s largest seller of online ads after Google, was losing about $545,000 in US ad revenue per hour during the outage, according to estimates from ad measurement firm Standard Media Index.

ARR