Users who go over their monthly data allotment will pay an additional fee based on their existing data plan.

FORBES: Did AT&T Boost its Profits by Charging iPhone Users Too Much?

Mobile phone users who want to disable their ability to send texts or data after they have used their monthly allotment may also be able to demand that service under the upcoming proposal, he said.

CNN: U.S. aims to regulate mobile 'bill shock'