Harmonizing Open Licenses among Online Databases of Enthusiast Communities: Challenges for the Legal Integration of Databases in the Japanese Visual Media Graph Project

The Japanese Visual Media Graph project has created a knowledge graph for researchers working on popular Japanese visual media by combining data compiled by various enthusiast online communities. In order to open up the knowledge graph to researchers around the globe, the databases needed to be integrated legally. This article discusses the hurdles we encountered in this integration process and the solution we settled on to overcome these problems. We provide a brief look at the complexity of the legal protection afforded to databases, which we found to be an important source of problems even for communities that attempted to apply appropriate open licenses to their data. Finally, we detail how using the CC BY-NC-SA 4.0 license as a smallest common denominator and asking communities to provide us with a separate tailor-made licensing agreement helped address both the concerns of the communities and the long-term needs of the projec