Twitter spells out its censorship policy: Just a couple of weeks after the SOPA/PIPA fight came to a head, Twitter pushed the discussion about online censorship a bit further when it announced late last week a new policy for censoring tweets: When Twitter gets requests from governments to block tweets containing what they deem illegal speech, its new policy will allow it to block those tweets only to readers within that country, leaving it visible to the rest of the world. Twitter will send notice that it’s blocked a tweet to the censorship watchdog Chilling Effects.

As the Guardian and The New York Times noted, much of the initial response among Twitter users consisted of complaints about censorship and the chilling of free speech in countries with oppressive regimes. The policy had critics elsewhere, too: BoingBoing’s Xeni Jardin said “it’s hard to see this as anything but a huge setback and disappointment,” and the international group Reporters Without Borders sent an open letter to Twitter questioning the policy and urging the company to reconsider. And later, BoingBoing’s Rob Beschizza pointed out that even though Twitter implied that it had already been blocking tweets at the request of governments (which would have made the new policy a reduction in censorship), it’s never actually done so — only in response to legal challenges on copyright issues.

But perhaps surprisingly, Twitter had far more defenders than critics among media observers. O’Reilly correspondent Alex Howard put together the most comprehensive roundup of opinions on the subject, praising Twitter himself for “sticking up for users where it can.” Two free-speech advocates, Mike Masnick of TechDirt and the Electronic Frontier Foundation’s Jillian York, made similar arguments: When a government is demanding censorship, Twitter can either refuse and be blocked entirely in that country, or it can comply. Twitter, they said, has chosen the latter in as limited and transparent fashion as possible.

Others, like The Next Web’s Nancy Messieh, commended Twitter for shifting the censorship focus to the government — as Reuters’ Paul Smalera argued, the gray box noting that a tweet has been censored in a certain country is a black mark for that government, not Twitter. The broadest argument in Twitter’s defense came from sociologist Zeynep Tufekci, who, in addition to these arguments, also praised Twitter for its transparency and for allowing users an easy way to circumvent censorship.

Still others weren’t firmly on either side regarding the policy itself, but pointed to larger issues surrounding it. Media prof C.W. Anderson said that while Twitter did the best it could under the circumstances but showed it doesn’t have any values that override its place as a business: “non-market values are, in the long run, incompatible with the logic of the market, and what Twitter is trying to do now is reconcile what it believes with what the market needs it to do.” Tech pioneer Dave Winer called for people to learn to be able to organize themselves outside of Twitter’s infrastructure and the possibly of censorship.

In a pair of thoughtful posts, GigaOM’s Mathew Ingram advised caution in trusting Twitter, recognizing that like Google and Facebook, it’s a business whose interests might not align with our own. The EFF’s York and Eva Galperin encouraged users and observers to keep a close eye on Twitter in order to keep them accountable for adhering to their professed beliefs.

Facebook goes public: Facebook’s much-anticipated filing for a public stock offering came on Wednesday, and The New York Times and Danny Sullivan at Marketing Land have the best quick-hit summaries of the S-1 document. The big numbers are mind-bogglingly big: 845 million monthly active users, $5 billion in stock, $3.71 billion in revenue last year, $1 billion in profit. Of that revenue, 85% came from advertising, and 12% came from the social gaming giant Zynga alone. (All Things D has the background on that relationship.) And when you average it out, Facebook’s only getting $4.39 in revenue per active user.

Aside from the numbers, among the other items of interest from the filings was its risk assessment — as summarized by Mashable, it sees slowing expected growth, difficulty in making money off of mobile access, competition from the likes of Google and Twitter, and global government censorship as some of its main risk factors. There’s also Mark Zuckerberg’s letter to shareholders, annotated with delightful snark by Wired’s Tim Carmody, which includes the explanation of a company code Zuckerberg calls “The Hacker Way.” Forbes’ Andy Greenberg made one of the first of what’s sure to be many comparisons between The Hacker Way and Google’s “Don’t Be Evil.” GigaOM’s Mathew Ingram took note of the grandiosity of Zuckerberg’s stated mission to rewire the world.

Two main questions emerged in commentary on the filing: How much is Facebook really worth? And what happens to Facebook now? To the first question, as The New York Times pointed out on the eve of Facebook’s filing, the company’s massive net worth is a stark indicator of the booming value of personal data collected online. The Columbia Journalism Review’s Ryan Chittum took the opposite tack, wondering why Facebook gets so little money out of each of its hundreds of millions of users before concluding that “Facebook is still a young business figuring out how to sell ads and figuring it how aggressive it can get without ticking off users.”

To the second question, Mathew Ingram noted that going public is usually a way for tech companies to get the financing they need to build up for some major growth — something Facebook has already done. So, he asked, is this just an attempt for Facebook’s employees and backers to cash out, and the end of the company’s most productive growth phase? Leaning on tech entrepreneurship leader John Battelle, Wired’s Tim Carmody and Mike Isaac reasoned that Facebook is mature enough already that in order to attain the growth it’s promising, it needs to be in the midst of some massive changes as a company. A couple of guesses at some of those specific changes: More ads and purchases of tech companies (Fast Company) and a big ramp-up in mobile ads (Marketing Land).

Murdoch’s candor amid scandal: The phone-hacking scandal at Rupert Murdoch’s News Corp. has continued to spread (rather quietly here in the States, but much more prominently in the U.K.), and it may have turned yet another corner with the arrest last weekend of four journalists from News Corp.’s Sun, significantly deepening the scandal beyond the now-defunct News of the World, where it began.

News Corp. has also turned over an enormous new trove of data which, along with the arrests, could begin to seriously threaten News Corp.’s other British newspapers, including the Times, according to the Guardian’s Nick Davies. British j-prof Roy Greenslade reported that many Sun staffers are worried that they may not be part of News Corp. much longer.

In the midst of all this, Murdoch’s feisty Twitter account continues unfettered, prompting praise from The New York Times’ David Carr for his refreshing candor. Mathew Ingram agreed that this “sources go direct” approach should be viewed as a boon, not a challenge, to serious journalism. The AP’s Jonathan Stray had perhaps the best summation of the relationship between sources using their own platforms and journalism: “When they want you to know, sources will go direct. When they don’t… that’s journalism.”

Reading roundup: It was a relatively quiet week outside of the big Twitter and Facebook stories, but there were still some cool nuggets to be found:

— Facebook’s relatively new Twitter-like Subscribe feature continues to draw complaints of rampant spam. Those criticisms have been led by Jim Romenesko, but this week the New York Daily News and Slate’s Katherine Goldstein chimed in, voicing concerns in particular about inappropriate comments directed toward women. Meanwhile, Mashable’s Todd Wasserman said Subscribe is ruining the News Feed.

— Big news in the journalism-academy world: Columbia and Stanford are teaming up to create a new Institute for Media Innovation, thanks to a $30 million gift from longtime Cosmopolitan editor Helen Gurley Brown.

— Jay Rosen posted an inspiring interview with the Chicago Tribune’s Tracy Samantha Schmidt, gleaning some useful insights on how to nurture an innovative and entrepreneurial spirit within a large organization, rather than a startup.

— Megan Garber of The Atlantic presented the results of a Hot or Not-style study that determined what type of Twitter content people like. Here’s what they don’t like: Old news, Twitter jargon, personal details, negativity, and lack of context.

Rupert Murdoch photo by David Shankbone and original Twitter bird by Matt Hamm used under a Creative Commons license.