Dataharvest 2025 - the European Investigative Journalism Conference

Solomon's investigation, "Who Owns the media", mapped the media owned by the top 10 oligarchs behind the biggest media conglomerates in Greece and, more importantly, it mapped the oligarchs' broader businesses. We identified more than 800 companies in sectors such as shipping, energy, sports, banking, and real estate, and searched business registries in more than 30 countries. The data were published in an interactive network diagram and a dedicated website.

We will present the methodology for dealing with large amounts of data, how to find companies of the same owner, and investigate business registries all over the world. We will work on case studies of specific companies and deal with the possible difficulties involved. The plan is to give attendees the tools to take this investigation and apply it to other countries.