Privacy concerns and information disclosure: An illusion of control hypothesis Laura Brandimarte and Alessandro Acquisti – Carnegie Mellon University Motivation Attitudes/behavior dichotomy: even though people seem to be very concerned about privacy violations, they reveal a lot of private information, especially on the internet. Example: online social networks According to a survey by the Pew Internet & American Life Project, April 2007, about the use of online social networks by teenagers: 82% of surveyed profile creators posted their first name online and 29% also posted their last name (11% on publicly accessible profiles); 79% included pictures of themselves; 61% published the name of their city or town; 29% posted their address and 2% added a mobile number. Possible consequences Positive –Signaling –Self-representation –Socialization But also negative –Stalking (and cyber-stalking) –Identity theft –Price discrimination –Lost employment opportunities –… Possible explanations Rational cost benefit analysis (Posner, 1978; Stigler, 1980) Awareness (Samuelson, 2001) Trust (Culnan & Armstrong PUT YEAR) “Behavioral” explanations (Acquisti, 2004) –Prospect theory (Kahneman & Tversky, 1979) and optimism bias –Hyperbolic time discounting and Immediate gratification We suggest one concurrent explanation: “ILLUSION OF CONTROL” Control over information dissemination does not necessarily imply control over information access/usage. Still, people may conflate the two concepts or they may give more importance to control over dissemination of private information than to control over access/use of that information by others, resulting in “too much” disclosure Two studies: Study 1: survey-based randomized experiment, manipulating control over mediated or unmediated publication of personal information Study 2: survey-based randomized experiment, manipulating control over probability of publication of personal information Our approach: do people respond to manipulations of control over publication of information, even if accessibility/usage don’t change – or indeed decrease? If our hypothesis is correct, we should observe larger willingness to reveal when subjects have control over publication. Design Subjects: students of Carnegie Mellon University recruited on campus Complete online survey Justification for the survey: creation of a university networking website Questions focus on students’ life on and off campus: multiple choice, Yes/No, Rating and open-end questions; include quasi-identifiers + privacy intrusive and non- intrusive questions as rated by subjects independently in a pre-study Dependent variables –Response rate (whether subject answered or not) –Admission rate (whether subject admitted to some behaviors) Explanatory variables –Treatment –Intrusiveness –Demographics (age, gender) Study 1: Profile automatically created vs. profile created by researcher Control group “No question/field is required. With the answers you provide, a profile will be automatically created for you, with no intervention by the researcher, and published on a new CMU networking website, which will only be accessible by members of the CMU community, starting from the end of April. The data will not be used in any other way.” Treatment group “No question/field is required. The answers you provide will be collected by the researcher, who will create a profile for you and publish it on a new CMU networking website, which will only be accessible by members of the CMU community, starting from the end of April. The data will not be used in any other way.” Hypothesis: Loss of control over publication should decrease willingness to disclose private information, and especially so for the most sensitive questions: It is not the publication of private information per se that disturbs people, but the fact that someone else will publish it for them Study 2: Profile automatically published vs. profile published with 50% probability Control group “The information you provide will appear on a profile that will be automatically created for you. The profile will be published on a new CMU networking website, which will only be accessible by members of the CMU community, starting at the end of this semester. The data will not be used in any other way. NO QUESTION/FIELD REQUIRES AN ANSWER.” Treatment group “The information you provide will appear on a profile that will be automatically created for you. Half of the profiles created for the participants will be randomly picked to be published on a new CMU networking website, which will only be accessible by members of the CMU community, starting at the end of this semester. The data will not be used in any other way. NO QUESTION/FIELD REQUIRES AN ANSWER.” Hypothesis: Loss of control over publication should decrease willingness to disclose private information even though, statistically, the probability of third parties accessing/using it is halved in the treatment condition Expected Results Control over publication leads to more revelation of private information, especially for privacy intrusive questions Control leads to admit more to some sensitive behaviors People seem to care more for control over publication of private information than for control over access and use of that information When someone other than themselves is responsible for the publication, or when the publication itself becomes uncertain – which reduces the probability of access/use by others – people refrain from disclosing Results from a pilot study confirm these hypotheses Response rate for each question – Study 1 Response rate for each question – Study 2 -I've never looked through a keyhole without finding someone was looking back. -- Judy Garland, actress -- -Relying on the government to protect your privacy is like asking a peeping tom to install your window blinds. -- John Perry Barlow, founder of the Electronic Frontier Foundation --