Although obsolete and insecure as it transmits data in clear data, Telnet remains particularly prevalent in Industrial Control Systems (ICS), operational technology (OT) environments, and certain government networks, where aging infrastructure is common and modernization cycles are slow. Many programmable logic controllers (PLCs), SCADA systems, and network devices deployed in these environments were manufactured before SSH became the standard, and were designed with Telnet as their sole remote management interface. Replacing or upgrading such systems is often prohibitively expensive, operationally disruptive, or outright impossible without vendor support — which may no longer exist for legacy equipment. In government contexts, long procurement cycles and strict change control processes mean that insecure protocols can persist for years even after vulnerabilities are publicly known. This makes Telnet exposure in these sectors especially dangerous: the systems behind it frequently control physical processes — power grids, water treatment, manufacturing lines — or handle sensitive government data, meaning a successful exploit can have consequences far beyond a typical IT breach.