Why can I add members to FB groups instead of just inviting them?

Question

I was under the impression group membership is voluntary - that you can't add someone to a group, but rather you can invite them.

I want to create a Facebook entity that:

1. Is open to everyone - everyone can leave or join at will
2. The only one that can make use X be in the group is an action by user X
3. Will be accessible to users that aren't signed to Facebook

A group doesn't seem to follow rules 2 and 3. Should I use a Fan page ? Or ... what is the best Facebook entity to capture this?

Answer 1

You don't want a group. You want a page.

http://www.facebook.com/home.php?#!/help/?faq=16140

Since groups look similar to Facebook Pages, what’s the difference between them?

Groups and Pages serve different purposes on Facebook. Groups are meant to foster group discussion around a particular topic area while Pages allow entities such as public figures and organizations to broadcast information to their fans. Only the authorized representative of the entity can run a Page.