Twitter has been flooded with memes about the outage. One user, named Moses, wrote: "NOT AGAIN... Instagram is DOWN?"

       Another, named Jeff, wrote: "What's up with Instagram?.. it's not even 4 days and it's already down again."

       Facebook is also down for the second time in a week - with users reporting difficulties logging in to both applications.

       Instagram is also owned by Facebook.

       Facebook has used Twitter to issue the following statement: "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."

       Once again, multiple people have taken aim at Facebook CEO Mark Zuckerberg.

       As the memes flow in on Twitter, the usual 'have you tried turning it off and on again' has proven popular once again.

       Amod K said: "It's happened again, It's happened again... Mark Zuckerberg.. It's happened again!!"

       Another took aim at social media altogether with Tim Trautmann Photo saying: "Since I have started abandoning Facebook and Instagram, I have connected with more friends, acquaintences, and former colleagues. I find that rather interesting."

       On Monday, Facebook and its subsidiaries Instagram and WhatsApp went dark after a router failure. There were thousands of negative headlines, millions of complaints, and more than three billion users were forced offline. On Tuesday, the company’s week got significantly worse.

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