private social network

Hi,

Was wondering if we can customize SharePoint 2013 to function as a private social network?

The core features are:

1. The web site (SharePoint) should be able to support many sub-groups
2. Each sub-group will have an ‘admin’ (a user from within the sub-group) that will basically accept/deny user request to join the sub-group or disable a user’s account in that sub-group.
3. Users will have the ability to determine, from users within the private network, who can see their contents.

An example is userA is in sub-group01 and there are say sub-groups 01-10.

UserA wants to create a thread in the discussion board and limits the audience to only those in her group (sub-group01).

On the other hand UserA could upload a video / pictures and grant access to those in her 'Friends' group (assuming UserA can create groups from people within the private network)

So, basically userA will have two main views; one view will be those only from sub-group01 and the other view is from content that’s in the private network that others have granted her access to see.

I think this might be feasible with SharePoint, but will it be pulling teeth to get this model to work?

Thanks in advance for your thoughts!

Thanks