Not just pilots.. passengers too, as the article says. Its not just forgetting to turn them off. Its ignoring the instructions. I think a lot of passengers don't believe there is a real safety concern. They're probably right. Otherwise, we'd have planes falling out of the sky on a regular basis. Proving the link wouldn't be difficult at all.

Anyone see the Myth Busters episode? Well, its a TV show made for entertainment, I know. But they went to great lengths to try and create interference on a Falcon 2000 (if I remember right). They didn't totally debunk the myth.. but their result was similar to a common maintenance entry.. "Unable to duplicate malfunction on the ground."