Analysing Countermeasures Against Privacy-Invasive Software

User privacy is widely affected by the occurrence of privacy-invasive software (PIS) on the Internet. Various forms of countermeasures try to mitigate the negative effects caused by PIS. We use a computer forensic tool to evaluate an anti-spyware tool, with respect to found PIS over a four years period. Within the anti-spyware tool PIS was slowly identified, caused classification problems, and formely classified PIS were sometimes excluded. Background information on both PIS and countermeasure techniques are also presented, followed by discussions on legal disputes between developers of PIS and vendors of countermeasures.