3b monthly users would mean nearly half of the entire world's population is on Facebook at least once per month. No matter how you shake it, that's simply not a realistic number, even before you consider people that live in areas with no internet, or regimes that disallow sites like Facebook, children too young to even possibly use Facebook, so on.

It wouldn't surprise me if the total number of real users, not counting bots and alt accounts, is probably ~1b or less.

HN lives in a bubble. Almost everyone I know uses FB daily. These are legal numbers and shouldn’t be too much off.

That's not growth, it's just logged in users navigating the web and FB counting anybody that hits their APIs. Facebook is dead.

Growth can be gained from the shape of the graph.

Sure, you can buy the lies you want