The development of the metaverse presents novel ethical challenges to society. There is a lack of knowledge of the potential metaverse and its effects on society. In this article, several ethical challenges of the future metaverse are discussed to responsibly prepare for the metaverse. A systematic literature review was conducted that showed the void of literature, meta-information of the state of the field, and level of maturity of the research. After defining the metaverse concept and reviewing its constructs, we present an overview of ethical challenges for the metaverse which ask for governance awareness and responsible action in the future. These ethical challenges have been clustered in the following pairs: Privacy & Freedom, Duplicate & False identities, Abuse & Manipulation, Trade & Ownership, Censorship & Surveillance, Democracy & Participation, and Regulation & Control. Related to these pairs, we also show some potential governance topics as a research agenda for the metaverse.</p
