Read the EULA and decide for yourself, or ask for legal advice.
The way I read the hard copy left behind by the installer, is that I may attach only one computer to the cable modem. I never violate this rule. It does not say anything prohibiting me to attach other PCs to the PC connected to the cable modem, nor does it state that the computer receiving internet access through cable has to be stand alone and not connected to anything else. Your mileage and interpretation may vary
The way I read the hard copy left behind by the installer, is that I may attach only one computer to the cable modem. I never violate this rule. It does not say anything prohibiting me to attach other PCs to the PC connected to the cable modem, nor does it state that the computer receiving internet access through cable has to be stand alone and not connected to anything else. Your mileage and interpretation may vary