If you are familiar with the **shred** command, you know it is an easy way to make sure sensitive data is *really* deleted. Shred overwrites a file with random data before deleting it, so that the original data cannot be recovered. Shred works by overwriting the data *in place*, or over top of the original file. But what if the file has already been deleted? One way to destroy the data is to overwrite all unused space on the drive (or partition) with random data.