The contribution "Open Information Sources - Information Society and the Internet" is an introductory entry to the upcoming series of search, extraction and analysis of data and information from open information sources. The following articles will address the issue of data and information extraction from open sources, which can be from both the public and private sectors, are freely accessible on the Internet in a structured and machine-readable form. Individual contributions will be devoted to selected open sources and possibilities of their practical use for identification of persons and their activities in the digital environment. This series is intended not only for specialists working in the field of search, identification and clarification of cybercrime, but also for the general public interested in increasing their computer literacy.