Facebook has announced that in the last 3 months of 2020 they removed approximately 1.3 billion fake accounts from their platform. That means that Facebook has now deleted almost 16 billion accounts since 2018, which is equivalent to deleting their entire monthly active userbase fives times over.
Whack-a-mole
Removing tens of millions of fake accounts every single day has become routine for Facebook, like an obscene game of whack-a-mole, in which perpetrators hope to slip through Facebook's net in order to try and defraud its users, spread misinformation or perpetrate a scam.
A quick Google search reveals just how big a problem Facebook has on their hands. Within a few seconds of searching we found 3 websites offering to sell verified Facebook accounts, with "real" photos, ages and information for somewhere between $10-15 per account (bulk discounts exist even in shady deals it seems).
Moderating fake accounts is arguably the most important part of Facebook's wider moderation strategy. Misinformation, hate-speech, nudity, fraud and drug sales are all often perpetrated through fake or pseudonymous accounts.
Facebook recognises the battle it has on its hands, and it employs 35,000 people to help it moderate its content. Although algorithms catch a lot of the harmful content, much is still flagged by actual human moderators, some of whom have suffered PTSD from some of the content.