Mastering Linux Security and Hardening - Second Edition

Setting and enforcing password and account expiration

Something you never want is to have unused user accounts remain active. There have been incidents where an administrator set up user accounts for temporary usage, such as for a conference, and then just forgot about them after the accounts were no longer needed.

Another example would be if your company were to hire contract workers whose contract expires on a specific date. Allowing those accounts to remain active and accessible after the temporary employees leave the company would be a huge security problem. In cases like these, you want a way to ensure that temporary user accounts aren't forgotten about when they're no longer needed. If your employer subscribes to the conventional wisdom ...