Sometimes patent holders use them to piss off an entire group of fanatics. Take this guy (Gell) that holds the patent for using a hot air corn popper to roast coffee beans. It works great in small batches, but no one can move forward with the concept because the Gell threatens to sue anyone using the concept and has not ever taken the concept to production. He is one of the most disliked people in the home roasting world... And he will go to great lengths to protect it...