Anyone who still has medibuntu in their Linux repos should remove it. If they don’t, they’ll see error messages similar to this when they perform their periodic sudo apt-get update command:
Something wicked happened resolving 'packages.medibuntu.org:http' (-5 - No address associated with hostname)
http://packages.medibuntu.org precise Release: The following signatures were invalid: NODATA 1 NODATA 2
Some Google searches imply this is a DNS issue when in fact, medibuntu has gone offline.
The simple fix is to remove medibuntu from your repository. There’s a single command that can do this for you:
sudo sed -i '/^deb http:\/\/packages.medibuntu.org*/d' /etc/apt/sources.list /etc/apt/sources.list.d/*.list
Thanks to this forum thread for the details.