Comcast says it could begin capping monthly data for all its customers within the next five years, a change that could potentially end up costing some heavy internet users additional fees. Speaking at a media summit in New York earlier today, Comcast executive David Cohen said that he expects the company to move entirely to a \usage-based billing model\ in the next five years, while adding that most customers dont go over their monthly allotment. Comcast currently has what Cohen described as a \series of pilots\ in various parts of the country that determine how much data monthly internet subscribers get. In places like Alabama, Atlanta, and Tennessee, theres also what Comcast calls a \flexible-data\ option that is limited to 5GB, but offers a credit if users stay under that amount.