Even if they hadn't, they did the right thing here. Note that Lamebook struck with the lawsuit first. It would've been easy enough to ignore Lamebook and just go after bigger trademark infringers on a case by case basis, but since Lamebook struck first, they actually had to strike back, because if they allowed that lawsuit to declare that Lamebook doesn't infringe on the Facebook trademark, there would be 200 <something>-book sites tomorrow created by copycats, and Facebook would be powerless against any of them because of the Lamebook judgment.
