John Schwartz in the New York Times:

"Many sites, including the online version of the Encyclopedia Britannica, display the seal. Other organizations might simply back down. But Wikipedia sent back a politely feisty response, stating that the bureau's lawyers had misquoted the law. 'While we appreciate your desire to revise the statute to reflect your expansive vision of it, the fact is that we must work with the actual language of the statute, not the aspirational version' that the F.B.I. had provided."

It's beyond me why the FBI would do something like that, tweaking the law and everything. They must know they'll be ridiculed for it.