File Wiping and Disk-on-Key
Most vendors selling security software that deals with removable devices or with flash storage mediums such as Disk-On-Key (DoK) provide the functionality of file wiping (often called shredding) from the removable medium. This feature allows the user to erase sensitive files that are no longer needed, in a way that (presumably) prevents them from ever being recovered; even if forensics gear is involved.
I find file wiping to be a useful function. Software that permanently destroys files is available on PCs since the early 80’s and has always been handy. File encryption utilities also use file wiping to remove the original plaintext file after encrypting it.
The one concern I have is about the reliability of these tools when they run against particular files that are stored on flash memory, such as USB DoK or SD cards.