The aim of this report is to ask the question “in what circumstances, if any, can the FOI [Freedom of information] tools mySociety builds be shown to have measurable impacts on the ability of citizens to exert power over underperforming institutions?”. It is the second of three documents, the first being a literature review of published literature on Freedom of Information (including both technical and non-technical issues), and is followed by a synthesis piece outlining ‘critical success factors’, including recommendations for mySociety and future implementers of FOI filer sites. Around 98 countries have implemented FOI laws, with many others in the process of implementing legislation and over 30 are known to have established FOI request sites, either official or those set up by CSOs [Civil Society Organisations] such as mySociety.