Luis, could you cite/link something that supports that view? It's not my interpretation of the licence...

CC-BY-NC refers to "Non-Commercial use" (i.e. "use", not organisation/institution/company), and it defines non-commercial as "not primarily intended for or directed towards commercial advantage or private monetary compensation".
  http://creativecommons.org/licenses/by-n...

My understanding of this is that it doesn't matter whether I work at a non-profit, non-commercial organisation or a for-profit company, as long as my use of the thing being licensed is not "primarily" aimed at making money, CC-BY-NC allows me to use it. This seems pretty reasonable to me; my understanding of it is that even an employee of a for-profit company could use (e.g. experiment with / learn from) the Challenge data, but they couldn't e.g. sell an average atlas built from it, or sell automatic segmentation software or services.

I'm not a lawyer though, and I would be interested to hear other thoughts on this.

Best,
Ged