The thing is, you have to judge the idea by how close it is to being realizable. I can say things like "Oh we should go to the moon", and that could be a great idea, but that doesn't mean it's patentable or that I should guard such an idea with an NDA :P
IDEAS!!!!!! it depends. they could be worth something. It could not. doh.
Most people guard them like they are mail order brides with questionable ethics.. i mean, we are in cryptoworld, so not so much here.. but outside of cryptoworld.