Rated 5 out of 5 stars

Its not working on responses from Facebook's ajax pages...
They give responses back that start with "for (;;);<actual JSON>" which breaks JSON.parse().
Perhaps you can somehow check for this kind of invalid json?
PS: im using 1.9.3

This review is for a previous version of the add-on (1.9.2). 

I'm not familiar with Facebook's numerous APIs (and their documentation pages insisting I login isn't very nice), if you like you can file an issue over on our Google Code project - then when I finish work on it, you'll be kept up to date. If you could mention a URL to test with (or if that would also require a login, attach a saved copy instead), that would be most useful.

In any case, this will require work I've yet to do for supporting JSON-P content (issue 13) - if I make that modular enough, adding support for this specific invalid JSON shouldn't be too difficult.