Credit: Nick Reddyhoff

Each time Facebook's privacy settings change or a technology makes personal information available to new audiences, people scream foul. Each time, their cries seem to fall on deaf ears.

The reason for this disconnect is that in a computational world, privacy is often implemented through access control. Yet privacy is not simply about controlling access. It's about understanding a social context, having a sense of how our information is passed around by others, and sharing accordingly. As social media mature, we must rethink how we encode privacy into our systems.

Privacy is not in opposition to speaking in public. We speak privately in public all the time. Sitting in a restaurant, we have intimate conversations knowing that the waitress may overhear. We count on what Erving Goffman called "civil inattention": people will politely ignore us, and even if they listen they won't join in, because doing so violates social norms. Of course, if a close friend sits at the neighboring table, everything changes. Whether an environment is public or not is beside the point. It's the situation that matters.

Whenever we speak in face-to-face settings, we modify our communication on the basis of cues like who's present and how far our voices carry. We negotiate privacy explicitly--"Please don't tell anyone"--or through tacit understanding. Sometimes, this fails. A friend might gossip behind our back or fail to understand what we thought was implied. Such incidents make us question our interpretation of the situation or the trustworthiness of the friend.

All this also applies online, but with additional complications. Digital walls do almost have ears; they listen, record, and share our messages. Before we can communicate appropriately in a social environment like Facebook or Twitter, we must develop a sense for how and what people share.

When the privacy options available to us change, we are more likely to question the system than to alter our own behavior. But such changes strain our relationships and undermine our ability to navigate broad social norms. People who can be whoever they want, wherever they want, are a privileged minority.

As social media become more embedded in everyday society, the mismatch between the rule-based privacy that software offers and the subtler, intuitive ways that humans understand the concept will increasingly cause cultural collisions and social slips. But people will not abandon social media, nor will privacy disappear. They will simply work harder to carve out a space for privacy as they understand it and to maintain control, whether by using pseudonyms or speaking in code.

Instead of forcing users to do that, why not make our social software support the way we naturally handle privacy? There is much to be said for allowing the sunlight of diversity to shine. But too much sunlight scorches the earth. Let's create a forest, not a desert.

Danah Boyd is a social-media researcher at Microsoft Research New England, a fellow at Harvard University's Berkman Center for Internet and Society, and a member of the 2010 TR35.

Copyright Technology Review 2010.

 

Last month, Facebook finally crossed a line. The company announced that it would make certain user information--including a user's name, hometown, education, work, and "likes" and "dislikes"--permanently public.

Facebook's default privacy policy has gradually shifted to expose more user data to the wider Web, but the reaction to this latest change has been significant. Last week, a collection of European data-protection authorities known as the Article 29 Working Group sent Facebook a letter chastising the company for not allowing users to limit access to their social data. The letter follows a similar criticism of Facebook by several members of congress, such as Sen. Charles Schumer, D-NY, over the past month. The reaction from privacy advocacy groups, and from many of Facebook's users, has also been vocal.

Some experts also say that the increase in information disclosure could have a serious side-effect--opening up new opportunities for hackers. Kevin Johnson, a senior researcher with security firm InGuardians, uses Facebook as a starting point for his job: testing companies' network security. Many times, he says, the most significant vulnerabilities are not in hardware or software, but in a users' use of social networks. The information leaked on social networking sites can be used to impersonate a legitimate person, in order to recover a password, for example; or to trick users into opening a malicious file by making it appear to come from a friend or a colleague.

"As a penetration tester--as an attacker--Facebook's privacy settings have made my job easier," Johnson says. "In the past, before two years ago, we had to trick people into running a [rogue] application [to collect data]. Now, the majority of people out there--the bulk of Facebook--run under default privacy settings."

Pushed by a need to monetize the data entered by users, Facebook has increasingly loosened its privacy policies. In 2005, the company's original policy stated that no information would be shared with people "who [do] not belong to at least one of the groups specified by you in your privacy settings." By 2010, the policy had changed to one that focuses on sharing much more information, stating that applications and Web sites "will have access to General Information about you." The text of the company's privacy policy has grown nearly 500 percent and users are now required to navigate some 50 different privacy settings.

"Facebook says that they are introducing more privacy settings because they want to give users more control, but what they have done is make things more confusing," says Fred Stutzman, a privacy researcher and PhD candidate at the University of North Carolina at Chapel Hill. "Over time they have made changes that make people's information more open, because that is how they drive the use of the network."

"This is something that is different from how Facebook had been operating," says Kurt Opsahl, a senior staff attorney with the Electronic Frontier Foundation. "In the past, they encouraged sharing that information, but now they have taken information that many people consider private and made it public, and they did so in a very heavy-handed way."

Yet, as Facebook has grown, users have become savvier about their data security, Stutzman says. Students at UNC Chapel Hill, for example, have increasingly opted to set their Facebook privacy to the highest possible setting, with almost 60 percent of students using the "Friends Only" setting in 2008 compared with less than 20 percent in 2005. Stutzman says that people have to overcome their preference to run under the default settings and opt not to change them.

Alessandro Acquisti, associate professor of information science and policy at Carnegie Mellon University, argues that Facebook is likely counting on that psychology to limit the number of people who ratchet up the privacy settings. "What is happening, it is almost a bait and switch technique," he says. "Every time they change the status quo, they are getting people more and more adjusted to the habit of disclosing information. If you told people five years ago that all these different fields are public, they would say, 'No way.' "

Facebook says that some information--a person's name, her network of connections, and pages that she likes and dislike have always been public. The user's photo, gender, and current city have all been added to the must-be-public profile information, the company acknowledges, but it says that only a small fraction of users are changing their settings to restrict access to information.

"The overwhelming majority of users have made all of this information available to everyone," a spokesman says. "We've found that the small percentage who have restricted any of this information have intended to prevent contact from nonfriends."

However, Facebook may not find an easy way out of the current controversy. In February 2009, when users were upset about other changes to its terms of service, the company created its Facebook Principles, a list of promises of how the company would treat its users and their data, including that "people should own their information, they should have the freedom to share it with anyone they want and take it with them anywhere they want, including removing it from the Facebook Service."

The company has failed to live up to those principles, says the EFF's Opsahl. "It is not just a matter of, can Facebook weather the storm of criticism and keep their users--they have a real situation here," Opsahl says. "But they have an opportunity as well. They can try and fix this problem and regain their users' trust."

Copyright Technology Review 2010.

Enhanced image: A prototype app for smart phones matches live images of people to stored profiles and shows icons for social networking sites around their heads. Credit: The Astonishing Tribe

An application that lets users point a smart phone at a stranger and immediately learn about them premiered last Tuesday at the Mobile World Congress in Barcelona, Spain. Developed by The Astonishing Tribe (TAT), a Swedish mobile software and design firm, the prototype software combines computer vision, cloud computing, facial recognition, social networking, and augmented reality.

"It's taking social networking to the next level," says Dan Gärdenfors, head of user experience research at TAT. "We thought the idea of bridging the way people used to meet, in the real world, and the new Internet-based ways of congregating would be really interesting."

TAT built the augmented ID demo, called Recognizr, to work on a phone that has a five-megapixel camera and runs the Android operating system. A user opens the application and points the phone's camera at someone nearby. Software created by Swedish computer-vision firm Polar Rose then detects the subject's face and creates a unique signature by combining measurements of facial features and building a 3-D model. This signature is sent to a server where it's compared to others stored in a database. Providing the subject has opted in to the service and uploaded a photo and profile of themselves, the server then sends back that person's name along with links to her profile on several social networking sites, including Twitter or Facebook. The Polar Rose software also tracks the position of the subject's head--TAT uses this information to display the subject's name and icons for the Web links on the phone's screen without obscuring her face.

"It's a very robust approach" to facial recognition, says Andrew Till, vice president of marketing solutions at Teleca, a mobile software consulting company in the United Kingdom. "It's much, much better than what I've previously seen."

Till says that applying image and face recognition to the trend of posting photos on social networking sites opens up interesting new possibilities. "You start to move into very creative ways of pulling together lots of services in a very beneficial way for personal uses, business uses, and you start to get into things that you otherwise wouldn't be able to do," he says.

Polar Rose's algorithms can run on the iPhone and on newer Android phones, says the company's chief technical officer and founder, Jan Erik Solem. The augmented ID application uses a cloud server to do the facial recognition primarily because many subjects will be unknown to the user (so there won't be a matching photo on the phone), but also to speed up the process on devices with less processing power.

Academic and company research groups have developed augmented reality applications, which superimpose virtual objects and information on top of the real world, for more than a decade. But until the past year or so, all of these prototype applications required bulky headsets and laptop computers. With more powerful sensors, cameras, and microprocessors built into mobile phones, however, augmented reality applications have begun hitting the mainstream. Several apps take advantage of the GPS chips and compasses available in newer smart phones. For example, PresseLite's Metro Paris app and Acrossair's Nearest Tube provide iPhone users with directions to nearby subway stops.

But Gärdenfors calls such applications "relatively crude." They often obscure objects with labels, he notes, and are sometimes limited by the fact that location information may not be available. He thinks that many augmented reality services could benefit from including elements of computer vision to make information retrieval and label positioning more precise. "This could absolutely work for other kinds of objects, and I think we'll see that soon," he says.

However, Gärdenfors notes that using computer vision to identify buildings and other objects holds challenges that they didn't encounter in developing the augmented ID application. "With facial recognition, it's so obvious what you want to search for," says Gärdenfors. "With other objects, it may be harder to tell which item on the screen you want to identify."

Gärdenfors says that TAT has taken potential privacy concerns with the technology seriously from the beginning. "Facial recognition can be a kind of scary thing, and you could use it for a lot of different purposes." For that reason, the company designed Recognizr as a strictly opt-in service: people would have to upload a photo and profile of themselves, and associate that with different social networks before anyone could use the service to identify them. "You should only be able to look at people who have signed up for this," Gärdenfors says.

A concept video of the augmented ID application that TAT posted on YouTube last summer garnered a great deal of attention. Gärdenfors says the company often uses this strategy to determine which ideas justify further development. A live demonstration also received a lot of interest at the Mobile World Congress. "We're probably going to partner with some company over the next couple of months to take it to the next level and actually build [a product]," Gärdenfors says. While this will require partnerships with a device maker, a mobile service provider, and social networking services, the technology is developed enough that a commercial application could be ready in as little as a month or two, he says.

Copyright Technology Review 2010.