How are copyright infringements on the Internet responded to? This study outlines the international, European as well as national legal frameworks with a particular focus on the law of the EU Member States, France, the UK and Germany. As regards the analysis of national law, the study differentiates between enforcement mechanism against end-users directly and mechanisms that are directed against infringing materials as such. The study highlights the challenges faced when enforcing copyright online, needing as it does to strike a balance between identifying the right target and providing an effective, yet proportionate enforcement mechanism. In addition to the outline and analysis of national approaches in terms of compatibility with fundamental rights and European law, a focus is set on questions of digital evidence and technological feasibility/efficiency of individual enforcement mechanisms.