Protecting and Sharing - Mutually Exclusive?

After a long and really interesting discussion with a friend of mine we were discussing how I as a designer, and the other designers in my course protect our ideas, and have sense of collaboration and helping each other out, even when working on different projects. I was arguing the point when ideas, knowledge, experiences etc. are shared, this is when you get the most interesting, exciting and innovative ideas. By working alone, or being too precious or secretive about your thoughts this can surely only be a bad thing - for both the well being of the designer, and the quality of the design solution. The most creative designs come from the intersections of disciplines and the sharing of extreme ideas. I think these ideas can be really seen in real world applications in front of us in our own course where there is a huge emphasis on getting input from many different sources, advising others and sharing information (just look at our insights wall for the current Microsoft project).

My friend was questioning where do you draw the line with this? How do you protect your ideas, and prevent your big break through from being stolen by someone else? Is my notion idealistic and naive? How would you feel is someone made a big break off something you had told them?

Its a really hard line to tread, and obviously there needs to be some degree of caution, but how do you judge this? What are your thoughts on the matter, we would be really interested to hear them (if your willing to share them that is!)

P