You also have to format before setting up a new external hard drive to stash your Aperture Library. Sometimes, preparing an external drive for backups or copying items onto it also entails total obliteration of data. But accessory manufacturers tend to craft accessories or peripherals gravitating towards Windows because a vast majority of external hard drives come preformatted for Windows. Mac users format a n external hard drive before handing over to another person to erase existing data.
