As you most likely are aware of everything you do with a computer system might be logged and tracked in every last minute detail if you or someone else decide to do so. What most users are not aware of though is all the traces and data that you leave behind although none asked for it. This talk will give the audience an insight in the world of invisible surveillance and what kind of tracks we leave behind by merely using a computer system. The audience will also be introduced to how this data can be extracted and how the authorities, the employer or the user can benefit from this. The talk ends with a few examples of how to protect yourself from leaving unwanted traces behind.