Author: Lior Jacob Strahilevitz
Source: The University of Chicago Law Review, Vol. 72, No. 3 (Summer, 2005), pp. 919-988
Published by: The University of Chicago Law Review
Stable URL: http://www.jstor.org/stable/4495516
What facts are public and what facts are private? It is the fundamental, first-principles question in privacy law, and a necessary element in the two most important privacy torts, public disclosure of private facts and intrusion upon seclusion. This paper argues that insights from the literature on social networks and information dissemination can help provide courts with a coherent and consistent methodology for determining whether an individual has a reasonable expectation of privacy in a particular fact that he has shared with one or more persons. The social networks literature has generated theoretical and empirical insights about the probability that information disclosed to one member of a community will ultimately become known by a large segment of the community. Using these insights, courts can gauge whether the plaintiff's previously private information would have been widely disseminated regardless of the defendant's actions in a particular case. If so, the information in question was public, and if not, the tort law ought to deem the information private. This Article argues that such an approach, which treats the privacy question as an empirical one, is more attractive than any other method of establishing whether the plaintiff had a reasonable expectation of privacy in the information at issue.
"Imagine your deepest, darkest secret-a true, but deeply embar- rassing, fact about yourself. Now suppose that you awake one morning to find this secret suddenly revealed to everyone you know, as well as dozens of strangers. Most of us would regard such a turn of events as a personal catastrophe. Given the unappealing nature of this scenario, and the ease with which juicy secrets can spread among people, one might expect that we would play our cards close to our vests, refusing to reveal these embarrassing details to anyone. Yet it is likely that most of us have shared our most embarrassing details with other peo- ple: spouses, siblings, parents, best friends, clergy, psychiatrists, co- workers, or perhaps even strangers on transatlantic flights. Indeed, millions of Americans have shared their most intimate personal de- tails with dozens of strangers, for example, by participating in a twelve-step group or seeking advice in an online chat room. By common parlance, we still consider these facts to be "secrets" even after we have revealed them to a handful of people" (Strahilevitz, 919).
"The literature that I introduce herein explores the ways that in- formation flows through society. Studying rumor transmission has long been a subject of some interest among sociologists and economists, and a few more recent studies have focused on the dissemination of information about HIV status and other sensitive forms of personal information through an individual's social circle. Taken as a whole, this literature provides an informative, albeit incomplete, picture of how likely particular information is to spread through any given social network. I will review this literature, discuss some of its implications for privacy law, and then compare these implications to the analysis that courts have conducted in privacy tort cases. I will argue that social networks analysis is an indispensable tool for resolving disputes where the parties to a communication disagree about whether the recipient was entitled to share it with others.
This framework has significant implications for privacy law. In order to determine whether a particular fact known by some people will become widely publicized, one needs to know much more than how many people are currently aware of the fact. Rather, one needs to know where, within a social network, this information exists; what types of people have access to it; what the incentives are for subse- quent dissemination; whether the information must be aggregated with other forms of information in order to become pertinent; and what kinds of social norms facilitate or constrain subsequent dissemi- nation of the information. Information known by one hundred people might never be disseminated further, but the widespread dissemina- tion of other information known to only two people might be inevita- ble. The literature on social networks allows us to identify useful gen- eralizations about the ways in which information flows through soci- ety. Because information spreads in rather predictable ways, and pat- terns emerge in particular kinds of networks, courts can use these regularities to analyze the ex ante likelihood that previously private information will become widely known. Once courts understand how to do that, it becomes relatively simple for them to evaluate whether a particular fact about a plaintiff eventually would have become public if the defendant had not intervened. This is precisely the inquiry that privacy tort law demands" (Strahilevitz, 921-922).
For the individual, sharing information about herself can be help- ful even when intimacy is not involved. Although concerns about inti- macy provide the strongest justifications for protecting privacy, there are other reasons why society might value privacy as well.'0 Millions of Americans participate in twelve-step programs and support groups, where it has become completely normal to disclose to a score of strangers one's status as an alcoholic, bulimic, child abuse victim, heroin addict, AIDS sufferer, or gambler." Sharing information within these groups can bring the discloser helpful advice, as well as the sometimes substantial psychological relief associated with revealing certain secrets to people the discloser expects to never encounter again.12 We are, in short, constantly disclosing embarrassing informa- tion about ourselves to third parties, yet we often harbor strong sub- jective expectations of privacy when doing so. By creating causes of action for invasion of privacy, most jurisdictions have determined that the benefits associated with fostering this intimacy justify the costs of constraining communication. In this paper, I assume the correctness of that judgment, notwithstanding the criticisms that have been lodged against privacy tort liability.