This idea of an Internet "fast lane" would create an uneven playing field in the eyes of the Federal Communications Commission (FCC), which said established, deep-pockets companies such as Facebook and Google would have an edge over small startups. That could prevent the next Google or Facebook from succeeding.
Jen Yeh, a policy council for the advocacy group Free Press who was in the courtroom, said the three-judge panel could do away with what is called the "Open Internet Order."
"That order prevents content providers from paying for priority access to get to users," she said. "It prevents a tiered system of superhighways for the rich and slow speedways for the poor."
Most observers felt that by their questioning, two of the three judges leaned toward freeing Verizon from some of the control the FCC has over it.
If this case results in the FCC losing some of its regulatory authority over the Internet, said amalia deloney, policy director for the Center for Media Justice, it could lead to voices of dissent and the disenfranchised being blocked from the Web.
"We need to be able to have groups like Iraq Veterans Against the War be able to express their anti-war views within the current debate between the president and Congress on Syria," deloney said.
Yeh said it is not hard to imagine what would happen if Internet service providers were freed from the FCC's current oversight.
"There will be no government oversight of our communications network, and corporations will retain control over what content we see, how much we pay for that content," she said. "In other words, our Internet will start to look a lot more like our cable system."
Critics also said added costs would be passed on to consumers. The case could be decided late this year or early next year.