Greetings, I have had almost no such problems in practice rooms but rather in class rooms. To prevent moving of pianos in certain areas I have taken to putting a large eye hook into the wall (mostly brick or block) with a liberal amount of epoxy. A chain, just long enough to reach the padlock, is fed through the eye and around one of the posts in back of the piano and then locked witha padlock through the links. I think someone is funning you, except it costs you time, effort and a hernia. Newton
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