WhatsApp, Instagram and Facebook have all gone down this afternoon (Monday, October 4).
The three sites are all owned by Facebook, the big tech company headed up by Mark Zuckerberg, and share infrastructures. They stopped working a few minutes before 5pm.
The outage appears to be international, and there is no news yet of when the problem will be fixed.
The company took to Twitter to explain: "We’re aware that some people are having trouble accessing our apps and products. We’re working to get things back to normal as quickly as possible, and we apologize for any inconvenience."
There was still no further news of service being restored by around 10pm, but Facebook's chief technical officer Mike Schroepfer tweeted: "*Sincere* apologies to everyone impacted by outages of Facebook powered services right now. We are experiencing networking issues and teams are working as fast as possible to debug and restore as fast as possible"
Meanwhile, Twitter users were gleefully posting memes and comments making light of the issue.
The instant image-based social media site, Instagram, was bought by Facebook in a $1 billion acquisition in 2012.
Facebook went on to purchase WhatsApp in February 2014 for a $19 billion.