We have a customer with tons of data produced every day. They insisted on backing up the stuff themselves, though they had a maintenance contract with our company. Anyway, one of their administrators put a DAT tape into the drive every night and removed it the next morning, labelled it, and stored it in a closet. One day the disk crashed. They called us because they couldn’t restore the data from tape for some reason. It turned out that although they did put a tape in every night, remove it every morning, label it, and store it, what they forgot to do was run the backup script. They had a year’s supply of backup tapes, neatly dated, and all of them empty.