Licensing issues are always a big problem for any community, you can look at the whole tivoization debacle for an example in the linux community specifically.

Licensing issues are always a big problem for any community, you can look at the whole tivoization debacle for an example in the linux community specifically. Changing a copyfree project to copyleft is a huge problem. Projects deliberately choose a license that works with their business model, An upside to the copyfree model is incorporating the code into a proprietary project without releasing the code. It is of course in the best interest of the one using the code to keep it in sync and submit their patches with the open source project for security and performance reasons. But they are not forced to do so.