Yeah, I'm looking at getting one of the cheap teaser receivers at BBY and then activating it on a Privacy.com card or a giftcard or something, so they can't pull that even if I forget or am unable to navigate their cancellation hoops.
I recently tried to subscribe to XM radio using multiple pre-paid Visa cards (for the same reason you outlined above) and all were denied. It also seems that using a credit card that expires before your subscription lapses won't help you either. They will send a bill to your address on file and report you to a collection agency if you do not pay.
Giving expiring card information does not magically make you not liable for a charge. It just makes it harder for them to collect and (hopefully) harder for you to forget about the charge.