Data has become one of the strongest drivers of economic growth and innovation. However, this data-driven transformation brings various challenges and harms affecting our lives and environments across different domains and scales. In this article, we define the set of such harms as data pollution. Data pollution is a multifaceted phenomenon, entailing different dimensions and complex mechanisms, which we capture in one conceptual model using network thinking and cybernetics. We further analyse the policy landscape to comprehend the awareness level and responses to this phenomenon.