It caused a social media meltdown.
And frustrated users turned to Twitter instead.
Partial shutdowns at Instagram, Whatsapp and Facebook for several hours across the globe on Wednesday (March 14) and into Thursday (March 15).
It was one of the longest outages faced by the company in the recent past.
And DownDetector's live outage map showed people in the U.S., Japan and parts of Europe were affected.
The FacebookDown and InstagramDown hashtags were trending.
Insta proudly announced on Wednesday night - "Aanddddd we're back" Along with a GIF of Oprah Winfrey screaming in excitement.
No such update from Facebook though.
It said it's working to resolve the issue as quickly as possible.
Still no word on what caused the problem.
Facebook insisted the blackout wasn't down to a distributed denial of service attack.
That's when hackers use computer networks they control to send so many requests for information from websites that servers that host them can't handle the traffic and the sites become unreachable.