What happened to Facebook, Instagram and WhatsApp?

 In one of the longest and most widespread incidents of malfunctions in social networking sites, a large-scale global outage continued on Monday, affecting Facebook, Instagram and WhatsApp services, to include at least tens of millions of users, according to specialized sites.

wdsPpVI/AAAAAAAARYo/yHeBXIj9gHgj9hsGH5tpIRimY01JIubIgCPcBGAYYCw/w320-h213/AZ12.webp" title="instagram down is facebook down facebook outage is facebook down today facebook not working why is facebook not working is facebook down today 2021 whatsapp not working facebook and instagram down facebook down today WhatsApp down Facebook is down is whatsapp down why is facebook down social media down instagram and facebook down Messenger is instagram down today 2021 FB when will instagram be back up instagram outage facebook and instagram not working facebook messenger why is facebook down today" width="320" />

It wasn't immediately clear what caused the outage, however, and several security experts pointed to a technical problem with the Domain Name system as the likely cause.

A domain name allows web addresses to transport users to their destinations, and a similar outage that affected cloud services company AkamaiTechnologies Inc last July led to the closure of multiple sites.

A Facebook spokesperson did not immediately respond to a request for comment, according to CNN Business.

But the New York Times quoted the company as ruling out that the problem faced by the site as a result of electronic attacks.

DownDetector, which tracks outages by compiling status reports from a series of sources, including messages sent by users, has identified more than 50,000 incidents of people reporting issues with Facebook and Twitter.

Several users who use their Facebook credentials to log into third-party apps such as Pokemon Go and Match Masters have also reported problems.

"We understand that some people are having trouble accessing our apps and products," Facebook spokesperson Andy Stone said.

"We are working to get things back to normal as quickly as possible, and we apologize for any inconvenience."

Officials at WhatsApp and Instagram also found only the Twitter platform to confirm the service outage.

Facebook saw widespread outages with its suite of apps this year in March and July, but they didn't last that long.

Stocks tumbling

In Monday afternoon trading, Facebook shares fell 5.5% in trading, heading for their worst day in nearly a year.

The outage comes a day after a whistleblower appeared on US television to reveal her identity after a trove of documents were leaked to authorities alleging that Facebook knows its products fuel hate and harm children's mental health.

Data expert Frances Hogan, 37, has worked at companies including Google and Pinterest, but said in an interview with CBS's "60 Minutes" news program that Facebook was "much worse" than anything she's seen before.