Guilty as charged. :) The silliness of the gadget is only matched by the gullibility of the authorities who put them on the hire bikes. In my defence, I think I was right until that contract was granted. Still, I'd be interested in seeing any kind of statistical evaluation of any claimed effects.
I'd be interested in some research into just where drivers look when checking mirrors etc. I can't imagine many drivers look to the ground, where they would have to to notice this thing.
@Oliver Schick jinxed this. Now it's everywhere! Arrgghhh.