How can you hide data by marking bad clusters?

What will be an ideal response?

ANSWER: One data-hiding technique used in FAT file systems is placing sensitive or incriminating data in free or slack space on disk partition clusters. This technique, although not common now, involves using older utilities, such as Norton DiskEdit, developed by Symantec as part of its Norton Utilities suite. In Norton DiskEdit, you can mark good clusters as bad clusters in the FAT table. The OS then considers these clusters unusable. The only way they can be accessed from the OS is by changing them to good clusters with a disk editor.

To mark a good cluster as bad in Norton DiskEdit, you type the letter B in the FAT entry corresponding to that cluster when examining the FAT table. You can then use any DOS disk editor to write and read data to this cluster, which is effectively hidden because it appears as bad to the OS.