I can think of one good example of bad designs: Recently the models of mobile phones are designed badly because they are too big to be hold with one hand, for instance, when i commute on trains, I often see other people and they are holding their mobile phones with their two hands. They often use one hand to hold the phone and the other hand writing messages on their phone. It is very dangerous, because their hands are occupied so they cannot hold a handrail or strap, which is a huge safety risk.