Mixmaster is is an anonymous remailer software. It encrypts your email messages before sending them, it typically fires off the messages through a series of anonymous proxies, you can choose how many and what proxies you want on the chain, it also provides protection against traffic analysis by delaying the sending of the messages at [...]

When working using bash, zsh, ksh or any other Unix shell the default is to save the history of the typed in commands, this can become a security and privacy risk.
Stop the history file keeping a copy of typed in commands
This can be used any time  you like assuming you have administrator rights (using bash [...]