I recently made our meetup group private. A Meetup Organizer can choose to have their Meetup Group be public or private. When you look at a public group, you can see all the pages and all the content of that Meetup Group. You can see the member list, group calendar, photos, message board, polls, files, everything. When you look at a private Meetup Group, you can only see the 'Our Home' and 'About Us' pages. All the other pages are hidden. Only members of the Meetup Group can view those pages. So if you want more information about a private group, contact the Organizer.