Identifying users via their "Clickprint"
The Guardian has an article: "Is it possible to be identified by your 'clickprint'?" that discusses "Clickprints on the Web: Are there signatures in Web browsing data?" by Balaji Padmanabhan of
The Wharton School, University of Pennsylvania. The gist of the paper is that it is possible to differentiate between two users by seeing how they navigate around a site over a number of visits.