ubuntu

For some odd reason, a 2 second delay is included by default when accidentally entering an incorrect username and password combination. This is meant to be a security feature to prevent evil people from brute force attacking your password!

Edit /etc/lightdm/lightdm.conf and add the following to exsting section.

greeter-hide-users=true

It is mind blowing that these incredibly insecure options are enabled by default.

A more complete list of options is available in /usr/share/doc/lightdm/lightdm.conf.

Edit /etc/lightdm/lightdm.conf and add the following to exsting section.

allow-guest=false

For previous versions

When starting up an Ubuntu computer, for some odd reason it decides to give away all the user logins that are available on that machine. This isn't particularly secure. Yes, these details can be obtained by directly reading the hard drive, but this is significant effort compared to simply turning it on.

To disable the user list, there doesn't seem to be a user interface switch as of Ubuntu 10.04, but there is a command line way to do it.

I type pretty fast when I'm on the command line and periodically, for commands that don't really matter, I don't check what I've typed and just press enter. This is especially true for directory listings which I have "ls -la" pretty much hard coded into my fingers. This particular one I mistype as "ls- la" all the time.

On Ubuntu, and other "helpful" platforms, there is a package installed called "command-not-found" which will take about 2-3 seconds to come up with a list of command it thinks you might have wanted to type but you haven't got installed right now.