Railroads...

Railroads can now outsource train control. Wabtec's "Wabtec Cloud Positive Train Control Communication Solution" - "A complete turnkey hosted office solution for I-ETMS-based Positive Train Control (PTC) systems"[1] (Wabtec used to be Westinghouse Air Brake.)

Wabtec has had break-ins, but claims they only involved employee info, not control systems.[2]

[1] https://www.wabteccorp.com/digital-intelligence/signaling-an...

[2] https://industrialcyber.co/ransomware/wabtec-suffers-data-br...