Are Those Steps Worth Your Privacy?

Fitness trackers are increasingly popular. The data they collect provides substantial benefits to their users, but it also creates privacy risks. In this work, we investigate how fitness-tracker users perceive the utility of features provide and associated privacy-inference We conduct a longitudinal study composed four-month period use (N = 227), followed by an online survey 227) interviews 19). assess users' knowledge concrete threats that exposed (as demonstrated previous work), possible privacy-preserving actions can take, perceptions provided fitness trackers. potential for minimization mental models tracking ecosystem works. Our findings show participants aware some types information might be inferred from collected For instance, correctly guessed sexual activity could heart-rate data. However, did not realize non-physiological demonstrate high minimization, either processing locally or decreasing temporal granularity sent service provider. Furthermore, identify participants' lack understanding common misconceptions about Fitbit