Generally, the name and description of a Meetup group, as well as other content posted to the site, is owned by the person who posts that content as long as that person didn’t copy or take that content from someplace else.
For most groups that means that the Organizer has the rights to the group name, description etc., and each member has the rights to the content that they post, such as comments.
Unless there is an agreement between an Organizer and members of that group, an Organizer does not acquire ownership of content posted by members.
However, an Organizer or member does not establish or create any ownership rights in content simply by posting that content on the Meetup website. If another person or entity owns the content that was posted, that other person remains the owner of that content and the member that posted the content may have legal liability for using that content without permission.
For more information about intellectual property rights, see the following Help section entry:
Where can I get more information about the legal issues related to using Meetup?
Meetup does not claim ownership of any of the content posted by members. By posting content to our site, a member does not give to Meetup any ownership rights that they may otherwise have, although they do grant to Meetup a license to use that content. This is discussed in Section 4.2 of our Terms of Service.