Data is the new oil; this refrain is repeated extensively in the age of
internet tracking, machine learning, and data analytics. As data collection
becomes more personal and pervasive, however, public pressure is mounting for
privacy protection. In this atmosphere, developers have created applications to
add noise to user attributes visible to tracking algorithms. This creates a
strategic interaction between trackers and users when incentives to maintain
privacy and improve accuracy are misaligned. In this paper, we conceptualize
this conflict through an N+1-player, augmented Stackelberg game. First a
machine learner declares a privacy protection level, and then users respond by
choosing their own perturbation amounts. We use the general frameworks of
differential privacy and empirical risk minimization to quantify the utility
components due to privacy and accuracy, respectively. In equilibrium, each user
perturbs her data independently, which leads to a high net loss in accuracy. To
remedy this scenario, we show that the learner improves his utility by
proactively perturbing the data himself. While other work in this area has
studied privacy markets and mechanism design for truthful reporting of user
information, we take a different viewpoint by considering both user and learner
perturbation.