George won't pay for a parking spot in a garage because he would rather find a public spot (nonexcludable) for free. George backs into a spot while another guy comes in headfirst, resulting in the question, "Who is entitled to the space?" Insecure property rights have led to overuse and conflict. George says, "I was here first." The parking jam-up ruins street access for everyone else; everyone ends up fighting about property rights, even the police, who can't decide.
Elaine's new boyfriend, Jerry's mechanic David, has stolen a bedroom move from Jerry. Jerry wants him to stop using it, but Elaine wants to continue to enjoy it. In the end, Jerry ends up "selling" the property right for a cheaper bill for car repair.
Elaine comes up with the idea of selling only the top parts of muffins; within days her old boss has opened a muffin-top store, capitalizing on her idea. Elaine needs protection for her idea, which is the role of the patent/trademark system.