It's that I want to be given back things they do as well. I want them to contribute back.
This project does something, and it's pretty neat. If someone takes the project and has another clever idea on what to do next, I want to see it. I want them to reciprocate.
Dunno- maybe this doesn't make sense.
If your worry about people copying your code is preventing you from sharing, then open source and free software might not be for you.
I wouldn't mind if people used the code, etc. It's that I want to be given back. That's the trade off. Not paid, free code, must give back. You piggyback and find this other thing, then I want to see it too.