Online encyclopedia Wikipedia became the latest high profile website to announce its intention to stage a 24-hour blackout on Wednesday January 18 in protest of the proposed Stop Online Piracy Act, just days after Reddit confirmed to the world it was doing the same.

The decision that will affect around 100 million visitors to the English language version of the website was made after a month long discussion by its members. "This is by far the largest level of participation in a community discussion ever seen on Wikipedia, which illustrates the level of concern that Wikipedian's feel about this proposed legislation," a statement on the Wikimedia Foundation website read.

Wikipedia and Reddit are also joined by Anonymous, who will be staging a blackout on all communications between 8am and 8pm on the same day. Wikipedia's founder, Jimmy Wales took to Twitter yesterday proclaiming, "this is going to be wow. I hope Wikipedia will melt phone systems in Washington on Wednesday. Tell everyone you know!"

"Today Wikipedians from around the world have spoken about their opposition to this destructive legislation. This is an extraordinary action for our community to take - and while we regret having to prevent the world from having access to Wikipedia for even a second, we simply cannot ignore the fact that SOPA and PIPA endanger free speech both in the United States and abroad, and set a frightening precedent of Internet censorship for the world," Wales said in a longer statement on Wikipedia.

Despite being used as a springboard to spread the news across the internet, Twitter will not being taking part in the protests. "Closing a global business in reaction to single-issue national politics is foolish," Twitter CEO Dick Costolo tweeted after reading that Wikipedia would be closing its services for the day. After facing a backlash, he later clarified that he was responding regarding his firm's stance, rather than commenting about Wikipedia.

Other tech companies strongly opposing the new legislation such as Google, Facebook, Microsoft and Adobe have made no announcements either, and aren't expected to be taking part, although it is possible some of them might display links on their homepages as a sign of support.