I have a (sensitive) background in security, in short, I believe that the infrastructures MUST NOT connect to the internet. If you connect to the internet, it is a matter of time before it is breached.

In recent news

An unidentified hacker has accessed the computer systems for the water treatment facility in the city of Oldsmar, Florida, and has modified chemical levels to dangerous parameters.

Are there any specific important reasons to connect such important facilities to the internet?

  • How would you propose monitoring the operation of these facilities?
    – schroeder
    Feb 9, 2021 at 13:39
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    @schroeder Night shifts?
    – kelalaka
    Feb 9, 2021 at 13:40
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    Where is the boundary? Will you connect a nuclear facility to the internet or ICBMs facilities? What if the next time a hacker made more clever changes to the water system that the indicators show no problem?
    – kelalaka
    Feb 9, 2021 at 13:47
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    @reed I suppose the problem of collecting data can be solved by separating the monitoring systems from the systems that control the facility. The monitoring systems can be connected and the control systems disconnected. However, the hacker can still cause limited damage by making the monitor systems report everything as normal when it isn't.
    – nobody
    Feb 9, 2021 at 14:00
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    @kelalaka An un-networked ICBM is useless once enemy missiles head your way...
    – dandavis
    Feb 9, 2021 at 20:33

1 Answer 1


It is the common balance between ease of use and security. The most secure system I can imagine is a switched off system inside a physical safe in secured room in a strong building, with armed guards around. But to access it, you have to physicaly enter the building, go to the secure room, tell the guards why you are there, open the safe, switch the system on, do the job, and then revert everything, meaning switch off, put in safe, lock the safe, quit the room and the building. Phew...

Hiring human beings is quite expensive, so instead of having a bunch of employees each with a car and ready to go to the water treatment installations just to change some parameters, you just connect everything to internet, and then a single employee can control a number of remote systems. Furthermore, a rather good part of system maintenance can be performed remotely by the system provider, with again a serious money gain.

So serious organizations do an analysis of security risks, with the chance of occurence, the impact, and the cost required to eliminate of reduce each risk. From that point they can objectively decide to establish some actions to reduce some risks and accept others. Exactly like in real life scenarii, I have a lock on the main door at my home, to prevent casual bad guys to come in, but I know that if an important organization decide to break in, I cannot prevent it: the cost of securing all the issues (including the roof) is not acceptable from my point of view. So I accept that risk, and contract with an insurance company to partially transfer it.

But I agree with you on one point: when it comes to the IT world, many people for both their private and work life fail at doing that security analysis, and let sensitive information unprotected without even thinking of the possible impacts.

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    You can do remote control with your own network that is separated from the internet. You don't need to connect them, at all, to achieve the same level of automation. The Internet is just cheaper than building a separate network. Its all about cost.
    – Polygnome
    Feb 9, 2021 at 21:42
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    @Polygnome of course, but that wasn't part of OP's question. And even then, if you hack into a worker's home system, you can then start up the VPN, log into the plant and wreak havoc.
    – RonJohn
    Feb 9, 2021 at 22:31
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    @RonJohn I was talking about physically separated networks. And yes, it was. They ask why water treatment plants are connected to the internet. the answer alludes to ease of use (centralization and automation). You can get both effects by having a completely separated network. The reason why such a network isn't build is cost.
    – Polygnome
    Feb 9, 2021 at 22:33
  • @Polygnome "by having a completely separated network" which means having to run cables to the houses of every worker who needs remote access.
    – RonJohn
    Feb 9, 2021 at 22:48
  • @RonJohn: One can mitigate many security risks by having a VPN firewall bridges between a secure trusted network segments and the Internet, which won't allow any machines on the network to connect to anything other than other secure segments of the same network.
    – supercat
    Feb 9, 2021 at 23:23

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