One thing which mystifies me about this whole situation is that Facebook arguably benefits from Lamebook's presence. Lamebook isn't a substitute for Facebook, it's a complement to Facebook. Someone who enjoys Lamebook for its humor will probably try extra-hard to find entertaining scenarios among their own Facebook friends, meaning that Lamebook increases Facebook's usage. Why you'd want to shut down a company that gives you more traffic (and therefore revenue) for a relatively unimportant and legally dubious reason is beyond me.
Not to mention, of course, the fact that Facebook is already invoking the Streisand effect by going after Lamebook at all.
Not to mention, of course, the fact that Facebook is already invoking the Streisand effect by going after Lamebook at all.