Both Facebook and Instagram, which is owned by Facebook, appear to have crashed.
Hundreds of people have taken to Twitter to share the news and express their frustration.
According to some reports, Facebook is now alerting users to ongoing "maintenance," though it appears to be unscheduled.
UPDATE 14:05 EST: some Facebook and Instagram users are now reporting that both networks are working. Still other report that posts are still not appearing.
TL;DR Facebook and Instagram has crashed worldwide. Below are some Twitter reactions.
Facebook is down. I repeat #FacebookISdown
Facebook is down again. Instagram as well. What is a person to do? @JasonWhitely
Shutdowns can offer some perspective:
It is moments like these when I start to understand how attached I really am to facebook... #facebookdown
Most turn to Twitter in moments like these.
@instagram this break down of yours better be you fixing yourself and learning how not to screw everyone over
This is a developing story. Stay tuned for updates.