ROYAL CARIBBEAN CRUISES said it had begun terminating business relationships with companies that it considered to be "card mills" -- firms that RCCL said were "selling ordinary consumers access to benefits designed for actual travel agents." RCCL sent a letter to travel agents last week saying that its three cruise brands were taking the action "in an effort to prevent a growing and troubling trend within the travel industry." RCCL said that card mills' activities could have several negative effects, including "negative consumer experiences with these untrained agents" and creating an environment where "the traditional and full set of services we expect a travel agent to provide to consumers are, in fact, not provided, despite the payment of a full commission."