B. Technology in service of democracy and fundamental rights
9. Share data that is not traceable to a person. Such data is a public commons. Keep in mind that not all knowledge can be captured in hard data.
Collecting, combining, and analysing data allows governments to become smarter at designing and evaluating policies. But they should not keep the data to themselves. Sharing information with citizens is at the heart of democratic accountability. Data collected by or on behalf of governments – insofar as it is not personal data – must be considered a public commons. This data, whether it concerns the health of trees  or 3D models of cities, should therefore be available for everyone to access, use, and share.
The popular app FindToilet allows its users to find the nearest public toilet in Copenhagen and other Danish municipalities. It has been developed by a woman who suffers from urinary incontinence and provides highly relevant, up-to-date information for other people with and without incontinence. FindToilet collects open data from local governments and visualises it on an online map and in the app. All the collected toilet data is available for reuse by others.
Personal information can also be open data, provided that it is irreversibly anonymised and therefore no longer personal. Governments need to be open about the anonymisation techniques they use, and they should check these regularly in order to prevent the data from being able to be traced back to identifiable persons through new datalinks. Anonymised location data in particular is vulnerable to de-anonymisation.
Open data requirements must apply to all companies operating on behalf of or with the support of a government, and to those with a permit granted by a government. Everyone should be able to use this data, whether it be citizens who want to analyse their living environments or companies that want to develop new applications.
According to the city of Barcelona, “data can generate new monopolies and accumulations of wealth which accentuate inequality. However, they can help generate evenly-distributed wealth and give us a better understanding of people’s needs and how to elaborate appropriate responses.” Barcelona opts for the egalitarian scenario and chooses to treat data collected in the city as a ‘common asset’. That includes data that is collected by companies. This data, with the exception of personal information, is published in reusable formats on Barcelona’s open data portal.
Some citizens are willing to voluntarily provide personal data for the public good. In doing so, they should be able to determine the purposes for which their data may be used: for health statistics and medical research, for example, but not for the development of medicines that will be subject to expensive patents. Municipalities can promote such data commons.
It is important to remember that not all knowledge can be captured in hard data or figures. In order to be able to evaluate loneliness in the city, or the quality of a school, 'softer' information such as experiential knowledge is also required.
Further viewing & readingTalk: Francesca Bria, How Barcelona is giving citizens control of their data
Manifesto: Amsterdam, Tada - data disclosedTalk: Eileen Wagner, From open data to open knowledge
 Map of Amsterdam's trees
 Helsinki's 3D city models
 findtoilet.dk For other examples of reuse of open data, see the European Data Portal
 If there is a risk of de-anonymisation, it can be legitimate for governments to limit access to and reuse of anonymised datasets. See F.J. Zuiderveen Borgesius et al., Open Data, Privacy, and Fair Information Principles: Towards a Balancing Framework, 2015
 See for example Y. de Montjoye et al., 'Unique in the Crowd: The privacy bounds of human mobility', Nature Scientific Reports, 2013
 Municipality of Barcelona, 'Ethical and Responsible Data Management: Barcelona Data Commons', Barcelona Digital City blog, 2018
 Open Data BCN
 See for example the DECODE project