Few are likely to be connected to the internet, I'd say after perusing https://de.wikipedia.org/wiki/Sibas (German, translation should work).
>SIEMENS Sibas 32, 6FH6035-1A + 4x 6FH 9543-3BY60 + 6FH 9533-3BY60 + 6FH 9550-3AY60 + 3x 6FH9485-3A + 6FH9484-3A + 6FH9498-3A + 6FH9481-3B Antriebssteuergerät
7500 EUR, 28 kg (found after a quick search).
This is my point, actually.
You wouldn't be directly connecting the PC to the Internet. You'd connect the PC to the KVM switch's PS/2 and VGA connectors. The KVM switch present the corresponding virtual desktop to an appropriate user over the Internet using RDP or similar.
Again, I'm not sure such a product currently exists, but I assume it is, given the needs of data-center admins.
The salespeople probably make jokes about high-speed computers.