Verizon alters/optimizes (you choose which) mobile traffic

I wondered if the mobile telcos did this. Never had proof until this piece from the Register:

http://regmedia.co.uk/2011/02/04/verizonwireless_choke_contract.pdf

http://www.theregister.co.uk/2011/02/04/verzon_may_throttle_your_network/