Da Vinci's Purposeful Mistakes

puppetman writes "According to a story out today, Leonardo Da Vinci deliberately introduced mistakes in his inventions. The series, Leonardo, produced by the BBC, claims that simple mistakes were introduced; mistakes that would not become apparent until after the contraption was built. The series hypothesizes that this was either a form of patent protection, or a way of ensuring his work did not end up being used for military purposes (Da Vinci was a gay, vegetarian pacifist)."