Downdetector that tracks outages by collating status reports from a series of sources, said that they saw almost 14 million total reports for Facebook, Whatsapp, Instagram and Facebook Messenger said, "We are starting to see reports begin to decline now that Facebook is back up."
Facebook apologized but did not immediately explain what caused the failure. The firm owns Instagram and WhatsApp.
As the world flocked to competing apps such as Twitter and TikTok, shares of Facebook fell 4.9%, 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 resumption of service.
"To every small and large business, family, and 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%."
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.
"Facebook basically locked its keys in its car," tweeted Jonathan Zittrain, Director of Harvard's Berkman Klein Center for Internet & Society.
As the company was struggling to resume connection, Schroepfer said in a tweet, "We are experiencing networking issues and teams are working as fast as possible to debug and restore." He also apologized sincerely to everyone "impacted by outages."
During the crisis, Facebook workers also reported issues with using their company phones and equipment, and some have even been locked out of the building when their digital cards failed to function, the New York Times reported on Monday.
Other platforms such as Amazon and Telegram have been experiencing difficulties ever since the Facebook shutdown as well, possibly as many users turned to these alternative platforms instead of Facebook, and overloaded their systems.
The severe outage comes immediately after a whistleblower accused Facebook of repeatedly prioritizing profit over clamping down on hate speech and misinformation on Sunday.
"Strange that hours after a whistleblower calls out Facebook saying they engaged in a 'betrayal of democracy' that Facebook and other companies it owns are totally down." Donald Trump Jr. tweeted on Monday. "I'm sure it's a coincidence."
#Facebookdown and Whatsapp have become trending on Twitter as the world experienced several hours with only one large active social media platform out of the top four used in Israel, Whatsapp, Twitter, Facebook and Instagram.
Twitter became the hottest arena for the hours when Facebook was off the grid, and started a thread reading, "hello literally everyone." Many industrial giants responded to the tweet, including McDonalds, Microsoft Teams, Alexa, and the culprits themselves, Whatsapp, Instagram and Real Mark Zuckerberg, who tweeted, "Am also here literally. Lol," and assured the fanbase that he was working on the app issues.
Security experts tracking the situation said the outage could have been triggered by a configuration error, which could be the result of an internal mistake, though sabotage by an insider would be theoretically possible.
An outside hack was viewed as less likely. A massive denial-of-service attack that could overwhelm one of the world's most popular sites, on the other hand, would require either coordination among powerful criminal groups or a very innovative technique.
Facebook acknowledged users were having trouble accessing its apps but did not provide any specifics about the nature of the problem or how many were affected by the outage.
"We're working to get things back to normal as quickly as possible, and we apologize for any inconvenience," Facebook said.
Facebook has experienced similar widespread outages with its suite of apps this year in March and July.
Several users using their Facebook credentials to log in to third-party apps such as Pokemon Go and Match Masters also faced issues.
"If your game isn't running as usual please note that
there's been an issue with Facebook login servers and the moment this gets
fixed all will be back to normal," puzzle game app Match Masters said on
its Twitter account.
