Wikipedia is the only source of light in a "world without free knowledge".
I think this page/ announcement works so well; it needed to be simple and to the point. I love the extreme shadow and the soft black and the Times New Roman. This is nothing dramatic or radical or ohmygodshit!, but that's probably the reason for its success.
Of course, Wikipedia is not the only site protesting. But I do think that it does it more, well, elegantly, than the others.
On an aside: never realized how often I went to the Wiki page in a day; I just instinctively click on a link or google search result and then realize a split second later that it's been blacked out.