Back in CRT days I was given a tiny desktop fishtank with plastic fish that swam in it. I turned it on and my screen image started gently moving around. The f

Back in CRT days I was given a tiny desktop fishtank with plastic fish that swam in it. I turned it on and my screen image started gently moving around. The fish swam with magnets and having the little tank next to the screen was causing the screen image to move around.