Privacy and user profiling : Profile-based evaluation of what different third party services may learn about a user

Abstract: Online behavioural targeted advertising has become a leading method to increase theeffectiveness of advertisement online. The advertisement is based on information aboutusers’ internet activities collected by third party tracking services. However, there is a fineline between whether this should be considered a privacy leakage or an unharmful way toimprove the experience. This thesis presents a methodology for understanding and analyzing how significant personal information leakage to third parties is. To investigate theinformation leakage, a web crawler was implemented with the purpose to imitate fictiveusers browsing the web. The users’ activity online was based on the fictive user’s interestsand personal information. For every webpage visited, data such as text, URLs and screenshots were saved. The data were analyzed and the finding revealed that third parties generated targeted ads based on personal information regardless of the browser, user’s profile,and geographical location. However, we observed that targeted ads are a frequent practiceand noticed that categories valued more by advertisers are more intensely targeted.