Additionally, how the hell is this trademark infringement? We've been using the "Software Name for X" formula for decades to refer to programs that operate in conjunction with other systems. In this case this extension only works with Facebook, therefore the Facebook name is more or less required to describe the function of the product with any accuracy. It's not like he's written a third party app for Facebook or we made his own social network called Facebook, he's done nothing to damage the value of the trademark.

I'm generally a pro IP guy but this seems extremely draconian.