Online gambling in Europe is a challenge for all stakeholders – service providers, gamblers, regulators and academic researchers. Despite a lack of harmonization of national gambling-specific legislations and consequent legal uncertainty, online gambling is the most progressive online service in the European Union (EU). Service providers are supposed to promote and implement strategies and measures that ensure an acceptable level of gamblers’ protection and prevention of problem gambling. At the same time, the online environment offers numerous novel opportunities for business development. Data is the central online business focus and, for that reason, it can be used for multifold purposes. This paper discusses how data collected for identifying online gamblers could include additional functions, both negative and positive, from the gamblers’ protection perspective. Thus, the paper answers the research question: What are the tensions in gamblers’ protection that derive from the identification of online gamblers in the EU?