I don't share my most dangerous ideas. Ideas are the most powerful forces that we can unleash upon the world, and they should not be let loose without careful consideration of their consequences. Some ideas are dangerous because they are false, like an idea that one race of humans is more worthy that another, or that one religion has monopoly on the truth. False ideas like these spread like wildfire, and have caused immeasurable harm. They still do. Such false ideas should obviously not be spread or encouraged, but there are also plenty of trues idea that should not be spread: ideas about how to cause terror and pain and chaos, ideas of how to better convince people of things that are not true.
I have often seen otherwise thoughtful people so caught up in such an idea that they seem unable to resist sharing it. To me, the idea that we should all share our most dangerous ideas is, itself, a very dangerous idea. I just hope that it never catches on.