The ability for persons in you home or car to listen to the CD is fair use. The Internet/Wireless router isn't stating how many people you could have in your home using the signal, just like for wired ports. If you had a friend over surfing the internet on his laptop, that's fine.
The problem is when you cross properties. Now, it has extended beyond fair personal use to sharing beyond the terms the provider sold you. For some reason, some tech people seem to want to differentiate between tangible and intangible property. The owner of the source signal did not consent to the use of it beyond the customer. The owner is incurring an incremental cost for the added bandwidth of the person latching on (satellite has little or no incremental cost for additional subscribers).
The grey area of morality comes from people who somehow there's a difference when none exists.
