[ken_yap]

I saw that too when I was doing a Joomla installation for a client.

I believe it's a feature that's provided by Joomla itself and doesn't involve the Linux authentication. So you would have to read the Joomla doco. Also if you have a firewall, particularly a NAT border firewall, there would probably also be hassles with the port forwarding rules for FTP, which is traditionally problematic for firewalls because it involves two ports, one of which is transmitted inside the command stream at connection establishment time.

I didn't enable for my client because I have already set up a more secure sftp (over ssh) system for them. Also the ssh protocol is easy to port forward.