i don't see why not. In Apple's case, they don't own the music, they just charge for the bandwidth usage and credit card transaction fees. Not sure if Amazon is the same way.
It would be the right thing for them to return their cut since it's only chump change for them, but who knows if they'll actually do it.

if you go to your account online and click on rate and plan features you 'll see what they charge you. when you click on other charges, you get a screen that shows a breakdown, depending on your state/billing address.
here's New Jersey:

Additional Charges
The additional charges for new customers in your area are shown below, including explanations of each charge.
The amounts shown below are based on the highest fee/surcharge rates assessed in your state; your actual fees/surcharges may be less. In addition to the AT&T charges described below, you will be billed for mandatory taxes and fees imposed by federal, state, and local governments on wireless subscribers.

State NEW JERSEY
Regulatory Cost Recovery Charge 1.25
Federal Universal Service Fund 11.4%
State Universal Service Fund $0.00
Other AT&T Surcharges 0.00%