Re:Facebook's seized files published by MPs
by jacobwg on Wednesday December 05, 2018 @01:17PM
(#18610888)
I believe you're thinking of FBJS (https://github.com/facebook/fbjs), which is a library as you describe, whereas the comment above is referring to loading the Facebook SDK from Facebook's servers. Among other things, Netflix offers Facebook login, which would need the SDK loaded.
So this might be what you’re seeing, but normally it’s included in a precompiled JS application bundle.