Nowadays it is easy to track web users among websites: cookies, web bugs or browser fingerprints are very useful techniques to achieve this. The data collected can be used to derive a specific user profile. This information can be used by third parties to present personalized advertisements while surfing the web. In addition a potential attacker could monitor all web traffic of an user e.g. its search queries. As a conclusion the attacker knows the intentions of the web user and of the company he is working for. As competitors maybe very interested in such information, this could lead to a new form of industrial espionage. In this paper I present some of the techniques commonly used. I illustrate some problems caused by the usage of insecure transmission lines and compromised search engines. Some camouflage techniques presented may help to protect the web users identity. This paper is a based on the lecture "Secure Systems" teached by Professor Walter Kriha at the Media University (HdM) Stuttgart
