  Data aggregators collect large amount of information about individual users
and create detailed online behavioral profiles of individuals. Behavioral
profiles benefit users by improving products and services. However, they have
also raised concerns regarding user privacy, transparency of collection
practices and accuracy of data in the profiles. To improve transparency, some
companies are allowing users to access their behavioral profiles. In this work,
we investigated behavioral profiles of users by utilizing these access
mechanisms. Using in-person interviews (n=8), we analyzed the data shown in the
profiles, elicited user concerns, and estimated accuracy of profiles. We
confirmed our interview findings via an online survey (n=100). To assess the
claim of improving transparency, we compared data shown in profiles with the
data that companies have about users. More than 70% of the participants
expressed concerns about collection of sensitive data such as credit and health
information, level of detail and how their data may be used. We found a large
gap between the data shown in profiles and the data possessed by companies. A
large number of profiles were inaccurate with as much as 80% inaccuracy. We
discuss implications for public policy management.
