For the last two decades, lone wolf terrorists in Western countries have been significantly changing their modus operandi. Part of these changes and possibly even one of their causes is the increasing use of the internet by lone wolves. This article reviews the role of the internet in the preparation of a terrorist attack as well as during the process of radicalisation of lone wolves. The possibilities and methodical flaws of lone wolf identification on the internet are also discussed. Based on current knowledge, it can be said that the Internet still has a limited role for lone wolves during the preparation of their terrorist attacks. However, it has been demonstrated, that as an efficient communication tool, the internet is of considerable importance in the process of lone wolf radicalisation. The internet is also a place where lone wolves may leak indications of their future actions. These leakages may be utilised for the identification of future lone wolf terrorists on discussion forums or radical websites using semi-automatic methods. However, the biggest drawbacks of these methods is their inability to distinguish between future lone wolf terrorists and common radical authors with no real intention on committing any terrorist act.