The Association of Medical Research Charities in the United Kingdom has made an appeal to the public to allow researchers to access the data contained in their National Health Service medical files. Patient records are currently held by general practictioners in the UK, but soon this information will be integrated into a central National Health Service database, « care.data ». The data collected will then be accessible to researchers and to pharmaceutical companies in an anonymised format. The UK’s government is in the process of sending an informative leaflet to all 22 million households in the country to explain the plans for data sharing and explaining how residents can opt out of the this scheme. Medical research charities hope that the population will be favourable to this move and are embarking on campaigns to explain the valuable resource this data represents and its importance to avances in medical science, such as the development of treatments for rare diseases. However, the public will need to be convinced that their data will remain anonymous and will not fall into the wrong hands for this enterprise to succeed.