American technology companies have often faced tricky issues about how they operate in relation to authoritarian regimes in China, Russia, and elsewhere. But as revolution sweeps through the Middle East, three companies have found themselves central to the action in an unprecedented way. Google, Facebook, and Twitter are all confronting the kind of moral and political dilemmas that global corporations usually hope to avoid. Their differing reactions tell us a lot about their corporate values—in a deeper sense than that issue is usually talked about.

Google’s response has been the most exemplary. From its earliest days, Google has asserted an unusual claim to ethical behavior—its slogan is “Don’t Be Evil.” The company has, on occasion, shown itself willing to forgo profits and take risks that others wouldn’t to avoid violating its own principles. The best previous example was China, where Google pulled out of the search engine market instead of continuing to accede to government demands for censorship of results. There’s a biographical explanation for this kind of corporate policy decision. The company’s co-founder Sergey Brin’s experience as a child of Jewish refuseniks living under Soviet tyranny has influenced the company’s behavior.

In Egypt, Google went even further than it did in China by directly opposing an oppressive government. There has been no suggestion that Google authorized or encouraged Wael Ghonim to foster a revolution there. But, amazingly, Google did not distance itself from one of its executives trying to overthrow the Mubarak regime in his spare time. Google’s CEO, Eric Schmidt, said recently that he was “very proud” of Ghonim, and the company has made clear that it would welcome him back to his old job. This was not all Google did. When Mubarak cut off Internet access, the company developed a workaround that allowed users to send Twitter messages over phone lines. YouTube, which Google owns, also created a hub to promote videos from protestors in Tahrir Square. This sort of activism has provoked Glenn Beck—and the Russian government—to charge Google with being in league with the Obama administration in supporting Egyptian revolution. In fact, Google has walked a fine line on this point, providing tools to help undermine tyranny without directly embracing any particular group of revolutionaries.

You can contrast this response with that of Facebook. Facebook’s platform played the bigger role in Hosni Mubarak’s downfall. It was the “We Are All Khaled Said” page Ghonim set up in June to memorialize a businessman who died in police custody that became the cradle of the revolution. But Facebook the company, unlike Google, has hardly embraced the honor. Last fall, it removed the crucial page rather than allowing the administrator to protect his identity. Sen. Richard Durbin of Illinois sent Facebook a letter requesting that it amend its no-anonymity policy to protect democratic activists in the Middle East. Facebook said no. When the Tunisian government used a virus to obtain passwords of activists, Facebook couched its response in terms of protecting user privacy, not challenging a vile regime.

Facebook is such a powerful organizing tool that the question of its attitude toward those who use its product is in some ways irrelevant. But it is worth pointing that the company has never shown any sign of having the kind of core commitment to liberty that Google does. Where Google voluntarily pulled out of China, Facebook—which is blocked there—is desperate to get in. This, too, reflects the background and worldview of its founder. Mark Zuckerberg, a child of privilege, has never known a lack of political freedom. He has no obvious ideological leanings and his big outside investors include a radical libertarian and a junior oligarch. It is difficult to imagine Facebook—or most other technology companies, for that matter—passing up a major business opportunity because of concerns about human rights. Facebook’s overriding objective is the much more typical one of expanding its market while avoiding bad PR and staying out of trouble with governments that set the rules.

Twitter goes a step beyond even Google in its sense of anti-authoritarian mission. Where Google’s core value is freedom of information, Twitter’s is the slightly different one of freedom of expression. Evan Williams, one of the company’s two founders and until recently its CEO, started Blogger.com and went to work with his partner Biz Stone at Google when Google bought that company. Williams unambiguously endorsed Google’s decision to pull out of China, and has said his company is working to develop technology to let users evade government censorship in China and Iran. Last month, Stone stated, in a recent tweet, “Freedom of Expression is a basic human right,” which he and the company’s top lawyer elaborated on in a blog post titled “The Tweets Must Flow.”

As with the others, Twitter’s attitude reflects its culture—one that’s unconventional, insurgent, even at times mildly irresponsible. As a smaller, more freewheeling company that has postponed maximization of profits in favor of growth and experimentation, it has latitude to embrace not just liberal principle but specific challenges to authority. In an interview with Terry Gross aired on NPR’s Fresh Air this week, Stone said of the Egyptian revolution: “It’s important to credit the brave people that take chances to stand up to regimes. They’re the star. What I like to think of services like Twitter and other services is that it’s kind of a supporting role. We’re there to facilitate and to foster and to accelerate those folks’ missions.”

I don’t want to read too much into a single comment, but Stone’s statement seems to me to go slightly too far. It is wonderful to see technology companies standing up for principles of free expression and human rights. But when they shade into embracing specific movements, they may find themselves assuming unwelcome responsibility for whatever follows.

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