Kramer, at the beach in the Hamptons with friends, finds a rope dangling into the water and pulls up a pot full of lobsters. He serves them for dinner that night, and his host says that he's poached them from a commercial lobsterman. Kramer says, "What's the problem? There's plenty for everyone." This highlights the wedge between individual incentives and optimal social outcomes.
Kramer has forgotten where he parked his car in a multi-level parking garage of a shopping mall and the gang walk around for an eternity looking for the car. Jerry needs to urinate and Kramer encourages him to do so in a dark corner where no one can see him. While doing so, he is spotted by an officer, and held in the officer's booth. Later in the episode, George is caught doing the same thing.
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.