I don't want this to sound snarky but....
Do you know that they were invited and declined?
is it possible that no one asked them to join, or declined to let them join?
Do you know that they were invited and declined?
is it possible that no one asked them to join, or declined to let them join?
Wouldn't they be liable for every song, every photo, every video, every document their users store? Maybe they've got songs (mostly) covered via the agreements for iTunes Match, but the rest seem hard to pull off (especially since, IIRC, taking a picture (or video) of a copyrighted painting, sculpture, etc. can be infringement in some cases).