Poltergeist activity is generally thought of as being associated with one person. Usually the person in a teenage girl who is going through some kind of angst. Many believe the poltergeist is a physical manifestation of their angst. Historically many people who have been tormented by poltergeist activity have been said to be possessed. Many contend that poltergeist activity is caused by ghosts.
Common characteristics of the phenomenon are: the movement and hurling around of inanimate, often extremely heavy, objects, the opening and closing of doors and windows by no visible means, unexplained noises such as voices, moans, screams, explosions, crashes, raps, thumps, scratches and knocks on floors, doors and walls, heavy footsteps, bed-shaking, the breaking of household objects such as crockery, the destruction of garments, the throwing of stones, rocks and dirt, bad smells, mysterious fires, the appearance of pools of water on floors, the malfunctioning of electrical equipment, telephone ringing, the unexplained appearance of objects, apparitions and even physical assault. Stone throwing is very often the first sign of poltergeist activity, with the houses of victims bombarded by stones and bricks sometimes for days before any other kind of unexplained phenomenon occurs
Whatever the ultimate cause of poltergeist activity, it is clear that the person is haunted. They may be haunted by their own angst filled psyche, but they are haunted and no amount of moving or running can free the victim from their torment. One of the best documented poltergeist cases was the Rosenheim case, Dr. Friedbert Karger was one of two physicists from the Max Planck Institute who helped to investigate perhaps the most validated poltergeist case in recorded history. A 19 year old secretary in a law firm in Rosenheim, a small town in southern Germany, was seemingly the unwittting cause of much chaos in the the firm, including disruption of electricity and telephone lines, the rotation of a picture and swinging lamps which were captured on video (which was one of the first times any poltergeist activity has been captured on film) and strange sounds that sounded electrical in origin were recorded.
Another famous case took place in Macomb, Illinois in 1948. In this case, another angst filled teenager named Wanet McNeil was forced to live with her father after her parent's divorce. The girl and her father moved to her uncle's farm, just west of Macomb. Wanet was very unhappy with the situation and her emotions were high. In the weeks that followed, Wanet managed to start fires all over her uncle's farm with nothing other than the power of her mind. She had no idea that she was causing the phenomena.
My sister was tormented by poltergeist activity for several years. Her case was classic. She was going through a period of intense psychological disturbance and strange things started happening around the house. Loud banging noises were heard throughout the house at night. Objects moved on their own. At one point a stack of boxes that were against a wall on one side of a room were hurled across the room against the ping pong table, breaking it. My parents sheltered her from much of the activity. The activity became worse at night when she was sleeping and my parents didn't tell her about the strange things that happened. However, she was still constantly terrified by the little she did see. The activity stopped abruptly last year and has never returned, but it was clear that she was the one driving all the activity. She was the one who was haunted.