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Commons-based peer production is when a group of people coalesce around an object to collaboratively learn, and to add personal clarity and meaning. It is a process whereby information is transformed into knowledge*. The term was coined by Yochai Benkler, and it is at the heart-and-soul of social networking.
In order for peer production to happen people must have the rights to modify the objects that they are gathering about. Unless you can manipulate the objects you can't have peer production. It's that simple. All-rights-reserved , the default copyright attached by most of our institutions of higher learning prohibit people from making derivative works. Unless your copyright allows for derivative works you're wasting your breath even talking about social media and peer production.
If you want to do social media you have to start by defining the rules of engagement. That's what Creative Commons licenses do. They help you to find the middle ground that enables people to participate. They give you a standard, clear, and legally defensible way to describe what people are allowed to do.
* You could argue this point based on your definition of knowledge. I'll stand-by this statement in a general sort of way. I'm talking about a process by which people take a piece of information, contextualize it and give it meaning.