One of those security things that pops up every now and then is to use the secure erase feature of Mac OS X, located in Disk Utility. But you can access this same feature from the command line using the secureErase option in diskutil followed by the freespace option. The format of the command is: diskutil secureErase freespace [level] [device] The levels are as follows (per the man page as not all of these are specified in Disk Utility): Single-pass zero-fill erase Single-pass random-fill erase US DoD 7-pass secure erase Gutmann algorithm 35-pass secure erase US DoE algorithm 3-pass secure erase So for example, let’s say you had a volume…