Order of Multitudes

Where are the boundaries between public information and private data?

Photo by Jordan Rowland on Unsplash

Kamala Sankaram: That’s a very tricky question at this point because it should be that you have control over what is private data, that you get to decide what people see and what they don’t. Part of the problem right now is most people don’t realize what actually is publicly available. For me, I think that anything private is anything that you say is private. If you don’t want other people to see it, you should be able to control that. But there isn’t enough transparency for people to make that decision now. We’re in a place where everything is public, even things that you might think are private and have control over are not so private once they are in the Cloud. I explored this in my opera, Looking at You: once you put something on social media, even if you think that only your friends can see it, anyone can find it. The researchers that we were working with could actually find people’s social security numbers based on what information people have put online. 

In my opera, we were really trying to figure out how to ride the line of what is scary and what is actually harmful. In the libretto, the sequence of data mining was built to become increasingly invasive. We started off with things that were pretty innocuous like your hometown or your school. Did you post something about food? Are there pictures of you at a party? Who else is in the photos with you? But by the end of the show, three people in the audience get songs sent to them about their pet or their child or where they work. What was interesting was that you could find information about people who do not necessarily have a social media presence. Because they’re tagged in other people’s photos, this data is still available about them, even though they were not actually the people who put it online. Even if you are the most vigilant person about making sure your privacy controls are very strong, unless you are telling people specifically not to tag you or put you in things, you don’t really know what’s out there. It’s a web of connections that is not within your control. 

Alessandro Acquisti: In my view, there is no clear, nor stable, boundary between public information and private data. This is for both technical and psychological reasons. From a technical perspective, research on re-identification from the past two decades has taught us that it is often possible to infer sensitive, private information from seemingly innocuous, publicly available data; and to identify data even when that data is, allegedly, anonymous or anonymized. This has also caused, for instance, the demise of the very notion of “personal identifying information”—even just four non-unique data points about you may, in fact, uniquely identify you.

From a psychological perspective, the boundaries between what is considered public and what is considered private change from person to person (and even within the same person, they change according to context and conditions). Those boundaries also change from culture to culture, and definitely over time, under the pressure of technology and evolving social norms. Irwin Altman captured this precisely by referring to privacy as a process of boundary regulation which is inherently dynamic (not fixed) and dialectic (alternating between humans’ need to protect and to open up). So, in essence, these boundaries are indeed nebulous—but we did not simply “get” there; they have always been. The problem today is that those boundaries have become not just nebulous but also opaque: we no longer know, or can effectively control, how certain private information about ourselves will in fact remain private or will become public.


Alessandro Acquisti

Professor of Information Technology and Public Policy, Heinz College, Carnegie Mellon University

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Alessandro Acquisti

Alessandro Acquisti is a Professor of Information Technology and Public Policy at the Heinz College, Carnegie Mellon University (CMU). He is the director of the Peex (Privacy Economics Experiments) lab at CMU and the co-director of CMU CBDR (Center for Behavioral and Decision Research). He investigates the economics of privacy, spearheading the investigation of privacy and disclosure behavior in online social networks, and the application of behavioral economics to the study of privacy and information security decision making.

Kamala Sankaram

PhD, Composer, Vocalist, Performer, and Writer

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Kamala Sankaram

Kamala Sankaram is a composer, vocalist, performer, and writer. She is known for her work with emerging technologies, and she has been commissioned for her work by Glimmerglass Festival, Washington National Opera, Houston Grand Opera, Shakespeare Theatre Company, and Opera on Tap, among others. She holds a Ph.D. in Cognitive Psychology from the New School and is currently a member of the composition faculty at SUNY Purchase. 

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