Courtney Hunt posted a blog post

... Private social networks are also referred to as enterprise social networks, intranet 2.0s, social intranets, enterprise 2.0 platforms, social business platforms, digital communities, etc. The basic idea behind them is to provide 2.0 or social media ...

http://www.recruitingblogs.com/profiles/blogs/private-social-networks-every-organization-needs-them?xg_source=activity