Imagine you have a bunch of fishermen surrounding a lake. After a while, they notice that each year they catch fewer and fewer fish. One realizes that what they're doing is unsustainable and they need to change their practices. He buys a billboard that says, "We must stop fishing at the lake." The others correctly point out that he still fishes there. "Fine", he says. "I'll stop." So he stops, and his income stops. Eventually he can't afford to keep that billboard up. Meanwhile, the others are doing better than ever now that the man isn't taking any fish out. They use the extra income to put up billboards saying, "Fishing here is fine."

In general, I'm a big fan of leading by example. But in situations like open source where there's a tragedy of the commons effect, leading by example can simply mean deliberately putting yourself at a competitive disadvantage. Companies that pay open source developers are doing the right thing morally, but end up with less money available to compete against other companies that don't.

I don't know what the right solution is. Maybe it requires organized action and legislation. Maybe it requires the open source developers themselves to restrict who they let use their code. (Sort of like the fish choosing which fishermen get to catch them.) I don't know. I applaud what Cognitect is doing, but I don't know if it will have any ability to influence other companies that extract value from open source without giving anything back. It may just make them relatively more powerful.