Don't know the rules (They probably keep changing) but you can see it here in incognito mode.

Even if that was the case, I'd make an alt account no one knows about to be able to look at his tweets if I cared enough. The point I was making it is it's dumb to "Block what people can see" when they can get around it with a couple button clicks.

(And to be clear because I'm getting downvoting, I'm not saying blocking is bad, but the implementation is pretty dumb, and at least removing the "You can't see this message because he blocked you" should be removed.)