"I place my toothbrushes in a cup, so I should be safe right?"
NO! Unfortunately, leaving your brush upright in a toothbrush cup can also leave it exposed to airborne microbes or germs. In order to keep your toothbrushes clean from bacteria, it is advised to place it at least 5 feet away from your toilet. Furthermore, placing your toothbrush in a cup collects water, and over time, building stagnant water which is prone to the breeding of mosquitos and germs.