Mediums' "energy allies" usually act at their own discretion, though holding dear the image of their partisan and preacher. They have proved to be fond of practical jokes too, playing sometimes such tricks that are far from what the medium have expected. Telekinetic effects may take place in a rather unexpected and inconvenient for both the medium and the spectators way, which has been called by the German word "poltergeist". Such unpredicted CPW's jokes are also described by U.Geller: "Professor Taylor and I went to another room where there were still more laboratory equipment. His assistants took a piece of copper and linked it with a tiny wire to a special apparatus that was to register the subtlest changes in the metal. I was to bend the copper piece, as always, without touch, by merely concentrating my thoughts on it. I was making a great effort saying inside: 'be bent, be bent', but nothing happened. We stopped for a moment as it seemed a failure. Suddenly the copper started to twist so vehemently that the tiny wire broke off.
At that moment the professor noticed that a brass plate on a table in the laboratory opposite corner was perfectly distorted. He had been going to use it for another experiment… We went on working and several minutes later we heard a metallic sound in the far corner of the room, in the distance of about seven meters from us. It was that very piece of brass falling on the floor near the door. In another several minutes the copper piece, that had been lying near the brass one, slipped from the table and also landed near the door. We were both very much surprised. Soon a thick straight iron rod on the other side of the table fell to Dr.Taylor's feet and twisted before his very eyes <…>.
I was at a rather good distance from all those things concentrating all my attention on something else and perfectly unaware of what was going to happen. It seemed that the energy forces were enjoying practical jokes. I gained an impression that they were demonstrating a kind of cosmic, peculiar sense of humour".
The medium often mentions this CPW's habit to act independently: "Sometimes very strange things happen. I point at one spoon and some other spoons or forks are deformed on the table. I can't explain it". Or in another interview, discussing his laboratory experiments: "I do not at all always have everything going off smoothly. Sometimes I feel very much embarrassed for I can never be sure whether it'll click. You see, my abilities do not really belong to me, but to a certain energy outside me".