Visitors to Wikipedia's English-language site were greeted by a dark page with white text which said: "Imagine a world without free knowledge... The US Congress is considering legislation that could fatally damage the free and open internet.

Wikipedia has taken its English-language content offline as part of a "day of darkness" in protest at US anti-piracy laws that it says could "fatally damage the free and open internet" and "severely limit people's access to online information".

Right now, the US Congress is considering legislation that could fatally damage the free and open internet.