I had to setup and secure the new server I am using for my business over the last week. In doing so, I setup BFD to protect the server from automated attacks. It's important to have some sort of automated system to block "brute force," or automated attacks.
Script kiddies (no..not hackers) like to use tools they didn't write with shiny GUIs to try and guess the user name and password of an account on the system. They do this by running programs that guess different passwords for a user name rapidly.