Freedom isn't free. That's what all the conservative bumper stickers say. Yet what they mean by that is quite different from what I think. They mean freedom carries with it an obligation to fight, on behalf of the nation, however the government defines the national interest, and however that government may be constituted.
In the world of open source, which I cover at ZDNet, there is another way of looking at this question, as put to us by Richard Stallman (above). You are given something, free. You can use it, you can see it, you can change it, you can add to it. But in return you have an obligation to give your changes back to the community, in the same way the original software was given to you.
The whole idea of open source as a business movement is in fact a reaction against Stallman, and this sense that freedom carries obligations. Stallman calls his movement FOSS -- Free and Open Source Software.
Licenses other than the GPL, however they differ in their details, are simply a way to fudge this obligation in some way, in the interests of profit. You don't have to share, or you have to give us credit, or your improvements belong to me, or you can only share if it's going to certain people. Changing the obligation of freedom in the name of someone else.
One of the big business trends of 2006, by the way, is that GPL licensing grew among open source businesses, while licensing under other terms declined. Most notably, just recently, Sun decided it would make Java open source, under the GPL.
After giving this a lot of thought, I come down on Stallman's side. The obligation of freedom is to give it to others. Those who would take freedom of speech for themselves but deny it to others aren't calling for freedom, but its opposite. No matter how much they bleat that they are on freedom's side, they simply are not. Because they don't accept freedom's basic bargain. They demand absolute trust for themselves, but they can't really trust anyone else.
All these views of freedom, in the end, come back to the Internet. The Internet isn't a place or a process but a protocol. It's a way in which you can connect computers. It does not perfect man. It doesn't change man at all. It merely gives man another way to ask these old questions, another forum in which to battle them out.
IP and the U.S. Constitution hold that in common. The Constitution is "a republic, if you can keep it" in Franklin's words. We have the obligation to fight for what it really means, against all enemies foreign and domestic, even when those enemies hold the highest positions in the land. To continue it requires intelligent belief. Not the open-hearted, empty-headed belief in Santa Claus. The open-minded, mutual belief we give one another in marriage.