This DanWatch study looks into the linkages between mobile phones and unfair mining practices in developing countries with cobalt extraction in DR Congo as a concrete example. The aim of the study is to show how cobalt extracted with unfair mining practices, often involving severe human rights abuses, ends in mobile phones batteries. Secondly, the study will recommend a set of actions that mobile phone companies should implement if they sincerely wish to be socially responsible and proactively contribute to sustainable extraction of metals within their supply chains. [refers to LG, LG Chem, Motorola, Nokia, Samsung, Sony Ericsson (joint venture Sony, Ericsson), Umicore]