How Prevalent Is Idea Theft?

Call me paranoid, but I have an idea that I may want to submit for Lego Ideas; but I may also want feedback from other builders along the way. Do people steal the ideas of others? I mean, as Lego enthusiasts, we're big kids still playing with toys as a hobby... I'm inclined to believe that there's nothing nefarious going on. However, working as a professional artist; I've heard numerous tales of job applicants padding out their portfolios with the works of others... It happens. Has it been...