On the other hand, sharing a well formed idea (I don't know how to further define that)
It's easy to define, it's called a patent ;-)
Agreed. And if it's not patented, what's to stop you from implementing? And if it is, you should be able to prove your idea was prior. We don't have a first to file system here in the U.S.
But in essence, no, I don't agree DD. An idea is just that. The execution is 10x, at least, of the idea.
We now do have a first to file system (America Invents Act, as of 3/16/13). Some things are simple, and the idea is 90%. Other things can sound simple, but getting it to work is a bear.
In any event, if someone did steal this AND then filed a patent, it may not be valid if they didn't invent what is claimed. It is possible that they stole it, modified it, then filed on the modified version.