These are the slides for the LIBER 2021 panel discussion Why use Wikidata or not Description: Wikidata as an infrastructure is a gold standard for modeling and sharing information on the web, as it provides an open source infrastructure for modeling data, as well as for querying information. Consequently, libraries are increasingly making metadata on their collections available via Wikidata. According to the survey conducted by the LIBER LOD Working Group in 2019, Wikidata “stood out as the most common external resource that the projects were linking to.”1 In this panel session we seek to bring together speakers who have done research on or implemented Wikidata for library collections to discuss the advantages and disadvantages of sharing these information via the Wikimedia ecosystem and Wikidata specifically. The panel will include a presentation from Annette Dortmund from OCLC; Olaf Janssen from the Koninklijke Bibliotheek in the Netherlands; Julie M. Birkholz from KBR- the Royal Library of Belgium, and Matt Miller from the Library of Congress. The presentations will include the reasons for the use of Wikidata or not, as well as practical examples from three libraries implementing Wikidata each in different stages. Following these short presentations there will be an opportunity for attendees to ask questions to facilitate a larger discussion on the growing knowledge around the use of linked data and specifically Wikidata in libraries.