Though the Stop Online Piracy Act has the support from the likes of Hollywood, the music industry, and the U.S. Chamber of Commerce, many Silicon Valley firms say it effectively amounts to censorship. To show their opposition to the bill, some sites are planning a service blackout on Jan. 18. Hayley Tsukayama reports:

Wikipedia, Reddit and Boing Boing are planning to black out their services Wednesday to protest the Stop Online Piracy Act and the Protect IP Act by showing users the bill’s effect on Web companies. These companies object to language in the bills, which are aimed at stopping online piracy on foreign Web sites, that grant the U.S. government the right to block entire Web sites with copyright-infringing content on them from the Internet.

Wikipedia will block all of its English-language pages — the first time since the encylopedia’s 2001 launch that it has ever restricted access to those pages as a form of protest.

“[It’s] a decision that wasn’t lightly made,” the company said on its blog Monday. The decision to take down the free encyclopedia’s English pages was made with the input of 1800 Wikipedia users who voted overwhelmingly in favor of the blackout, according to statement from the Wikimedia Foundation.

It’s also a form of protest that isn’t for everyone.

Twitter, for example, has been a vocal opponent of both bills, but chief executive Dick Costolo said the service has no plans to participate in a blackout over the bills.

In a tweet reply to O’Reilly Media’s Alex Howard Monday, Costolo said that “closing a global business in reaction to single-issue national politics is foolish,” referring to suggestions that Twitter lacked the backbone of the other services by not shuttering its virtual doors in protest.

Costolo followed up by saying, “Not shutting down a service doesn’t equal not taking the proper stance on an issue. We’ve been very clear about our stance.”

Instead of pulling down the micro-blogging service — which many people use to run their businesses, organize activities and communicate important information — Costolo said the company will look into how it can use the platform to encourage discussion about the bills.

Technology titan Google did not join in on the blackout, but it is planning a protest of a different sort for Jan. 18. Hayley Tsukayama writes:

Google said Tuesday that it will post a statement on its Web site voicing its opposition to the Stop Online Piracy Act, joining a drive that will see Reddit, Wikipedia, and Boing Boing take their Web sites dark for a period of time on Jan. 18. Google’s actions will not be as dramatic as others — Reddit and Boing Boing will take their sites down for 12 hours starting at 8 a.m., while Wikipedia will black out its English content for 24 hours on Wednesday — but the company’s decision to use its U.S. home page means that its arguments regarding SOPA will reach a huge audience.

In a statement, Google’s news team said, “Like many businesses, entrepreneurs and web users, we oppose these bills because there are smart, targeted ways to shut down foreign rogue websites without asking American companies to censor the Internet. So tomorrow we will be joining many other tech companies to highlight this issue on our US home page.”

Other sites voicing their support for the Internet’s “strike” over the proposed piracy bills include MoveOn.org, the Cheezburger Network, Mozilla and Wordpress.

Lobbying against the bill has been furious, and on Tuesday, NetCoalition — which counts Google, Yahoo, Amazon, eBay and Wikipedia among its users — started a national radio and print advertising campaign against SOPA and its Senate counterpart, the Protect IP Act, focusing on the argument that the restrictions the bills place on Internet companies to police infringing material on their sites stifles innovation.

Why has the long-running debate over SOPA and PIPA suddenly gaining steam again? It may be because the White House weighed in on the bills over the weekend. Brad Plumer reports:

It looks like the uproar over Congress’s online-piracy bills is having a real impact. This weekend, the White House strongly hinted that it would oppose the current legislation. And key sponsors are edging away from the bills’ most controversial features.

Late on Friday night, the White House released a statement announcing that it “will not support legislation that reduces freedom of expression, increases cybersecurity risk, or undermines the dynamic, innovative global Internet.” That’s a huge shift, and it came in response to a petition asking President Obama to veto the Stop Online Piracy Act (SOPA) in the House, which would give content providers sweeping new tools to crack down on copyright infringement. True, the White House statement doesn’t oppose SOPA directly, but it’s a fairly clear condemnation of the flaws critics have pointed to in the bill. (See here for a basic rundown of what SOPA is, and why it’s generated so much controversy.)

It’s also a sign that momentum on online-piracy legislation is shifting dramatically. Just six months ago, these bills seemed all but inevitable. The Senate version of SOPA, the Protect IP Act, was being held up by one lonely senator, Ron Wyden, and most of the bill’s backers were confident of eventual passage. But critics and tech exports started pointing out that these bills could impinge on free speech and disrupt the workings of the Internet. Online communities like Tumblr and Reddit organized loud, boisterous, and often clever campaigns — the document-sharing site Scribd, for instance, made a billion pages vanish to protest the bill — and public opinion swung sharply. A Reddit campaign managed to persuade Paul Ryan to oppose the bill, for instance.

As a result, even the most ardent backers of the bill are now softening their support. Sen. Pat Leahy, a key sponsor of the Protect IP Act, has conceded that more study is needed for the provisions that would allow rogue sites to be delisted from the Domain Name Service (basically the Internet’s phone directory). Critics have warned that mucking with DNS could splinter the architecture of the Internet.

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