Jo thinks that people are trying to find him to kill him. When people walk by his apartment (to get into their cars or walk to the bus) Jo interprets this to mean that they are spying on his every move. As there are always people walking by apartments in the city, Jo thinks that there are always people watching him. He is always staring out the window and loses sleep worrying about people trying to come into his house. He forgets to eat and forgets to change his clothes. While at work, Jo is not getting his work done and is easily startled by anyone who walks by. His coworkers start to worry and feel uncomfortable around him. What kind of delusion is Jo experiencing?