[keycloak-user] UMA2: share with all users

Hello, Is there a way to share resources with all users? Or to share with groups? In my use case, I need to start with "open" situations, where resources are accessible. Some users can choose to restrict access to the resource, though. I was thinking of using a "isPrivate" attribute to my resource, with default to false. But maybe it's possible to use UMA instead: start with resource shared with all users, and let the users reset the sharings...