Wikipedia has joined sites like Reddit and the Cheezburger Network in blacking out this week to protest the much-maligned Stop Online Piracy Act (SOPA) and Protect IP Act (PIPA).

The founder of the site, Jimmy Wales, tweeted today, "I am just starting to do press interviews about the upcoming blackout of Wikipedia to protest #sopa and #pipa,” shortly followed by, "This is going to be wow. I hope Wikipedia will melt phone systems in Washington on Wednesday. Tell everyone you know!”

The protest will take place on Wednesday, from midnight to midnight EST (6pm Wednesday to 6pm Thursday New Zealand time). Only English sites will be affected, but it will cover the whole globe.

Instead of the usual content, the site will simply display a message explaining why the protest is taking place and what actions supporters can take.

The announcement comes as the White House responds to petitions protesting SOPA, recognising opponents’ concerns but not stating outright that the bill won’t go ahead.

"While we believe that online piracy by foreign websites is a serious problem that requires a serious legislative response,” the statement reads, "we will not support legislation that reduces freedom of expression, increases cybersecurity risk, or undermines the dynamic, innovative global internet.”

The statement never acknowledges that the bill in its current form does these things (with the exception of the section covering DNS filtering provisions); instead it simply requests more public input on the issue, while reiterating that anti-piracy legislation will be enacted in some form this year.

"Let us be clear – online piracy is a real problem that harms the American economy, threatens jobs for significant numbers of middle class workers and hurts some of our nation’s most creative and innovative companies and entrepreneurs.

"Washington needs to head your best ideas about how to clamp down on rogue websites and other criminals who make money off the creative efforts of American artists and rights holders.”

Even if SOPA is on hold for now, its corresponding Senate bill, PIPA, remains just as big a threat. In another of his tweets today, Wales says, "SOPA might not be dead, but in any event PIPA (PROTECTIP) is still going strong."

Update: The SOPA bill has been all but shelved, with California Congressman Darrell Issa saying House majority leader Eric Cantor assured him 'anti-piracy legislation will not move to the House floor this Congress without a consensus'.

Issa made the comment in a statement cancelling a related hearing that was due to take place on the same day as scheduled blackout protests.

"I am confident that flawed legislation will not be taken up by this house," the SOPA opponent says in a statement.

"The voice of the internet community has been heard."

Opponents will go ahead with blackouts at this stage, with the PIPA bill - SOPA's Senate counterpart - still up for discussion.