For all the 'non-believers', yes I know the page name "UFO-SCIENCE" is a little crazy, and yes, you could stumble across the effects of the sampling frequency of the camera, and that of the helicopters blades matching naturally. However, it is just as possible, as the page claims, that the helicopter sent a radio signal of the frequency of its blades to the camera, so that the movie could be made. This way, when the helicopters blades changed speeds the camera would still match the frequency and continue recording the illusion... I don't know how much helicopters change the frequency of their rotors but I am sure they had to when they were changing directions and hovering like the video shows.
Btw I didn't read anything about magnets on the page, so err, what?