What's an unauthorized device? If I fork chromium and make my own browser what makes it authorized or unauthorized? If I make a CURL request from my terminal is that authorized or unauthorized?

If FB blocked any requests from Firefox Focus they'd likely be in hot water from government agencies.

Do they have the right to block any other app?

“You shouldn’t be able to do something because it’s not allowed” is a tautological argument. Parent comment is arguing that it should be made allowed.

This kinda is how freedom works though. You're free to use whatever client you want, and Meta is free to implement API in a way that will not allow your client to call it.

Technically free and actually free are not the same thing.

So I should be able to steal from my neighbor because that's true freedom? Because you're using their resources and servers in a way they didn't authorize.

It's not stealing if they gave you the data.

They don't though. They're giving the data to the original client, not to the third party one. They're free to choose who they're giving the data to and you accept those conditions by using their product.

¯\_(ツ)_/¯

They gave you the data conditioned on an agreement not to use unauthorized clients, the same way any number of real-world businesses "give" you things subject to conditions, like the waffle maker in the hotel lobby which requires you to stay there overnight to use it.

What if your neighbor lends you a book, subject to the condition that you only read it to your sons, not your daughters? Are you stealing if you read it to your daughters anyway?

I don't know, because that's not a real agreement, unlike the hotel waffle maker and Instagram's client rules.