There's an update at the bottom of the post saying Google took it down...

You get a red ! button if you aren't logged into your Google account.

That supposedly means you are either not logged in or you are in any country that is not the USA. If the latter will last indefinitely.. wow, lame.

I can't see even a red button. What am I doing wrong? I'm outside USA, enabled it in /experimental. Using Chrome, Firefox.