The freedom to modify (Re:So how do we do it?) (Score 1)

Well, if you download the source code of a program and modify it to satisfy your needs, you have an advantage over "freeloaders" who only use the software but contribute nothing. These guys "punish" freeloaders because they scratch their own itches but freeloaders have no power over new features.

On the other hand, very few people customize their OS software and it's more and more uncommon when we get to very complex software like Mozilla or the Linux kernel.

The true freeloaders, however, are those who get the sources, modify the software to serve their purposes but don't give the modifications back to the community. I don't necessarily mean selling the software here (which is IMHO OK), or releasing a closed-source version (which is semi-OK). Lack of contribution from people who get a customization or financial advantage is the worst form of freeloading.

A punishment that seem to work to some degree is using a license that require contributing the changes. Some OS licenses don't require it (BSD), some do but allow not contributing modifications if the modified (binary) version is never released in public (GPL).