"No one is going to steal your idea. In fact, if your company is eventually successful, your original idea will only be one tiny contributing factor. And the guy you’re talking to can’t steal the 99,999 other reasons that will make your company a success (persistence, luck, people you hire, etc, etc, etc)"So, don't be afraid to share your ideas. Haha!
99% of the scenarios in the submissions may sound very ridiculous, but on one or more occasions it only seems too true. I think the site is very Dilbert-ish too. Enjoy!