In the US, Google blacked out its logo on its own homepage – although the same cannot be said for

Wikipedia today loads only a black protest page – unless you use a smartphone browser, in which case you can see the usual encyclopedia entries, according to the Daily Mail.

The move is to protest the SOPA anti-piracy act in the US.

Wikipedia’s black page states: “Imagine a world without free knowledge.”

Google had previously ruled out blacking out itself, but showed a black patch covering its logo, which seemed to make clear whose side it was on.

SOPA – or the Stop Online Piracy Act – in essence seeks to prevent online pirates from making music, film, TV shows and eBooks available free of charge.

But industry insiders argue that the proposed laws go too far and amount to violating freedom of expression, in that they attempt to censor the internet.

“If passed, this legislation will harm the free and open internet and bring about new tools for censorship of international websites inside the United States,” the Wikimedia foundation said.

Mozilla directed Firefox users to a new anti-SOPA homepage, while replaced its homepage with a call for action against the laws.

However, Twitter refused to join in, with its CEO reportedly calling the attempt to apply single-nation politics to a worldwide service “foolish”.