If the ISP sells "unlimited" access, then customers have
every right to use it without limit.
Indubitably. But customers are not free to pick and choose
among which provisions of the service agreement they want to
abide by. If the ISP provides unlimited access but limits
the account to a single host, then that is the terms of service.
The problem, as has been noted, is enforcement.
It is a single computer. If I have a dialup, as I have now, it is one
computer. If it NAT's other computers through it, I'm still using exactl
one connection. One IP.
Now, if I were to get two computers, and have both of them dialup, then
they'd have reason to complain and kick me off.
By the same token, a NAT box is one computer, uses the resources of one
computer. Only one computer is plugged into the cable-modem. Its a router,
but its still only one computer.
Also, 'terms and services' can be interesting.. Pulling out the nearest
``Without limiting the rights under copyright reserved above, no part of
this publication may be reproduced, stored in, or introduced into a
retrieval system, or transmitted in any form, or by any means ...
without the prior written permission ....''
-- Publication page of Simon Green's 'Deathstalker War'
Which claims, among other things that I cannot send this email, and I
cannot quote any extract, no matter how small, from that paperback. Both
of which are nonsense.