Here are a list of things I would like to add to srm.

1) Only destroys data of regular files but can unlink others as well.
2) Ability to use much more advanced patterns for destroying data.
3) Ability to recursively navigate and delete entire directory 
   structures.
4) Ability to verify that the pattern was written correctly.
5) Handle multiple files from the command line.
6) Interactively query the user before deleting each file. 
