I Never Signed Up For This!

Abstract

This paper presents a framework for automated, large-scale monitoring of email tracking practices across the web. Our system consists of two major components: a web crawler to programmatically sign up for mailing lists on websites, and a mail server to store and analyze the incoming mail. We then present our findings on several months’ worth of collected emails, examining common tracking techniques and evaluating their implications on user privacy. In particular, we find widespread leakage of users’ email addresses and a vast network of third parties behind pixel tracking.