Privacy Implications of Social Media Manipulation

[Commentary] The ethical debate about Facebook’s mood manipulation experiment has rightly focused on Facebook’s manipulation of what users saw, rather than the “pure privacy” issue of which information was collected and how it was used.

The key point is that the privacy impact of an interaction like this depends not only on which types of information are gathered, but also on which prompts were given to the user and how those prompts were chosen. Experimenting on users affects their privacy.

Now: What can we learn about the privacy impact of Facebook’s experiment? Facebook did learn some non-zero amount of information about the manipulability of individual users’ emotions. Given the published results of the study, the information learned about individual users was probably very weak, in the statistical sense of being correlated with the truth but only very weakly correlated, for the vast majority of users or perhaps for all users.

Ultimately, experiments that manipulate user experience impact users’ privacy, and that privacy impact needs to be taken into account in evaluating the ethics of such experiments and in determining when users should be informed.

[Felten is Director, Center for Information Technology Policy, Princeton University]