Time to set a license on our work?

Time has changed, also on Geni. Today thousands of genealogists all over the world are collaborating on the same tree. There are a few examples on similar projects, the greatest is Wikipedia. And we have to look at Wikipedia to see how we can improve our work.

A problem today is: "Who owns the tree?" Since thousands of people have worked on it, it is impossible to know what you own and what other owns. Therefor I mean it's time to let people make their tree free and open by licensing it under eg. http://creativecommons.org/licenses/by-nc-sa/3.0/

What do you think? Are you willing to open your work?