Here's the original story.
I do agree with this excerpt, though:
Exclusions for non-routable protocols are ludicrous. They are cyber vulnerable and make up most of the communications in utility operations.Media converters are rampant in ICS networks and effectively give serial-based devices, which the asset owner intended to 'hide' behind serial communication, an IP address thereby becoming addressable and reachable by a routable protocol.
Is a media converter the new "We're secure. We have a firewall and anti-virus"?