The fourth one (instagram) doesn't require login.

Side note: annoying that twitter/X requires login. I'd have sworn Elon said he was removing that requirement to login to view tweets (I think he discussed it with George Hotz).

Found it: https://www.youtube.com/watch?v=FkNkSQ42jg4&t=49m30s

Elon:

> This is insane. You shouldn't need a twitter account at all unless you need to write something

George:

> Why did you put the pop up back?

Elon:

> We should not be prohibiting read-only scroll

So there seems to be agreement that twitter shouldn't require an account to read (view) posts. The Twitter Space is from 23 Dec 2022 so perhaps things changed since.