To try to prevent others from joining this argument: twitter is currently not allowing you to read tweets without being logged in. Hence, it can be both available and not available.
If it cannot be read without logging in, then it is inaccessible. That's a choice twitter gets to make, but to claim tweets are accessible because some people can read them is no different from posting links to a private facebook group and saying "you just need to be a member of that group".
That said, I was saying it is inaccessible because I am getting error messages trying to load it.