All this operational technology is connected to a central system.
And as cyber-experts such as Jon Niccolls, from CheckPoint, explain, where there is connectivity, there is risk of cyber-attack:
"All the devices used to run a modern pipeline are controlled by computers, rather than being controlled physically by people," he says.
"If they are connected to an organisation's internal network and it gets hit with a cyber-attack, then the pipeline itself is vulnerable to malicious attacks."
How did the hackers break in? Direct attacks on operational technology are rare because these systems are usually better protected, experts say.
So it's more likely the hackers gained access to Colonial's computer system through the administrative side of the business.
"Some of the biggest attacks we've seen all started with an email," Mr Niccolls says.
"An employee may have been tricked into downloading some malware, for example.
"We've also seen recent examples of hackers getting in using weaknesses or compromise of a third-party software.
"Hackers will use any chance they get to gain a foothold in a network." Hackers could potentially have been inside Colonial's IT network for weeks or even months before launching their ransomware attack.
In the past, criminals have cause mayhem after finding their way into the software programs responsible for operational technology.
In February, a hacker gained access to the water system of Florida city and tried to pump in a "dangerous" amount of a chemical.
A worker saw it happening on his screen and stopped the attack in its tracks.
Similarly, in winter 2015-16, hackers in Ukraine were able to flick digital switches in a power plant, causing cuts affecting hundreds of thousands of people. pg slot