"Real social networks"? There is nothing in "social network" that requires the relationship to be equal in real-life or that you even know the identity of the person you're writing with. Most would consider Twitter social media, and most people I know constantly interact and discuss with people they don't really care who they are and that's not what's important anyways.

I would say in general, places where you interact with other people ends up building some sort of social network of it's insides.