Recommender systems have been gaining more and more attention lately. The number of online platforms that support the information needs and product search of their users by providing personalized suggestions have been increasing rapidly. However, there is also more and more discussion about role and impact of these systems, e.g., related to filter bubbles, echo chambers, fake news or micro-targeting. For some of these issues, personalization and recommender systems are held responsible. Users are becoming increasingly sensitive, and are demanding systems that mitigate bias and that are not just designed to increase the number of interactions.