Let's be clear: the Open Data movement is not about the pursuit of complete and unconditional openness. We know that it would be unwise to publish details of police patrol patterns, or the combination to the safe containing the crown jewels. We believe that fundamental reference data like ordnance survey maps, transport timetables, and company information should be freely available to all - information about objects, rather than information about people. Internationally, slightly different standards apply in different countries, but in the UK open data can be defined as "non-personally identifiable data produced in the course of an organisation’s ordinary business". However, between 'open data' and 'personal data' there is a large grey area, and inevitably the boundaries are sometimes blurry. Serious privacy issues usually arise when an institution sees individuals as objects.