I believe you're thinking of FBJS (https://github.com/facebook/fbjs https://github.com/facebook/fbjs), which is a library as you describe, whereas the comment a

I believe you're thinking of FBJS (https://github.com/facebook/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.