I've never seen this before, but this afternoon I started getting Firefox notifications that a popup had been blocked on Google.ca. After some searching and failing to find any references to it anywhere, I decided to unblock it to gather more information.
After unblocking it, running a search caused a popup to appear each and every time I run a search. The page identifies itself as a logger, but there's very little to it, as you can see from the screenshot below:
If I click the "options" link, another panel appears with a dropdown for logging sensitivities:
This only seems to be happening on Google.ca (doesn't happen when I force it to Google.com), and only in Firefox. Switching to Chrome shows no logger popup.
It does seem to be coming from Google, as HTTPFox doesn't show any non-Google domains being requested on page load. They're not HTTPS, so there's a possibility that something is being injected during transit, but I'm operating under the assumption that this actually is a Google page of some kind, albeit one that folks probably aren't meant to see under normal circumstances.
Has anyone else seen this? How do I shut it off?