As Prof. Lyons explains in the post: "Usage-based pricing is not inherently anti-competitive or anti-consumer. Rather, it is an alternative method of spreading costs across a network's customer base." As a result, heavy users pay more. "Tiered plans can also help make broadband more affordable to low-income consumers." Tiered or usage-based pricing practices are common throughout the economy.
On April 3, FSF published Prof. Lyons's Perspectives paper, "The Challenge of VoIP to Legacy Federal and State Regulatory Regimes." He also spoke at FSF's Fifth Annual Conference on panel focused on "The Right Regulatory Approaches for Wireline and Wireless Broadband Providers." The YouTube video for that panel is below.