Originally Posted by Tourist in MSN

I used to commute through a college campus to and from work. And even in winter there were a lot of bicyclists. In November through January when it was after sunset on my drive home I often saw bicyclists with blinkers attached to backpacks, or strapped to a small saddle bag, or some other piece of fabric that prevented them from carefully aiming the taillights. And they were often worthless because they shined towards the sky or pavement. Typically when I saw these blinkers, it was when I was only a few tens of feet behind them. Or, perhaps they were worse than worthless because the riders may have had a false sense of security thinking that they were actually seen.

I only use taillights mounted on a rack, seatpost or seat stay so that I can carefully aim them towards where the drivers behind me are.