Profile based evaluation of what different browsers and browser extensions may be able to learn about a user

Abstract: Information leakage online has become a marketplace where companies can profile users to gain revenue from personalized advertising. This thesis offers a deeper analysis into what part the browsers Chrome and Firefox play in this targeted advertising. Privacy focused extensions have become a common way for users to avoid being exposed to third-party trackers, and two such extensions are Ghostery and CatBlock. By adding these to the browsers, this thesis examines how ads are affected during online sessions. Through development of a Selenium web crawler, several online profiles were built with the usage of personas based on specific interest categories. By performing daily sessions of Google search queries, data was collected in the form of ads and HTML text. The data collection lasted for a period of 21 days, using 29 virtual machines and 6 personas. This data was further used to analyze the extent of personalization of ads as profiles were built over time. The results obtained show similarities in how ads are targeted in the browsers, as well as the level of personalization that occurs when using an extension. Results show no major differences in level of targeting between the used browsers, but clearly show that a personalization of advertising has occurred. The usage of extensions proved to be efficient in reducing the amount of ads that a user is exposed to. However, the usage of extensions did not decrease the percentage of targeting amongst ads.