Over five hours in a Washington, DC courtroom today, a coalition of net neutrality defenders squared off with the Federal Communications Commission, as the two sides made their case for and against the internet regulations.

The dispute is one of the most high-profile legal battles in the history of the internet, but there was no immediate sign of which way the three-judge panel overseeing the case would decide. By turns, both sides faced some sharp questioning from the judges for the US Court of Appeals for the District of Columbia.

The petitioners in the case argued that the FCC’s repeal was unlawful in several ways. The FCC failed in its analysis of the internet service market, failed to consider public safety, should not have blocked states from passing their own net neutrality rules, and erred in its determination of what a telecommunications service is, they said.

Is the internet like pizza delivery, or Uber Eats?

Some of those punches seemed to land, while others fell flat. The FCC changed the legal classification of broadband service when it repealed the rules, and that decision is a key point of dispute. But it was difficult to see whether the judges were swayed by the argument there. The analogies used to explain the different types of internet services turned increasingly complex: was the FCC treating the internet like a pizza, when it was more like a pizza delivery service? an attorney for the petitioners asked. And was modern internet service more like Uber Eats?

The public safety argument, however, seemed to emerge as an important point in the hearing. The FCC received a sharp interrogation from one of the judges, who questioned repeatedly how the agency’s decision might affect first responders. Santa Clara County, which appeared in court to defend the net neutrality rules, noted that the repeal may not be enough to solve a crisis. (Last year, the county made headlines over a throttling incident during a California wildfire.)

If someone is throttled during a crisis, the court noted, it hardly matters if someone is punished much later. “Post-hoc remedies don’t work in the public safety context, and that, unless I missed it, wasn’t addressed anywhere in the order,” the judge said.

The court may be tied up with the case for a long time

The FCC’s main point in the hearing was that the net neutrality rules harmed broadband investment, and that the repeal improved the market — an analysis the petitioners strongly reject. An attorney representing internet service providers also argued that there wasn’t enough evidence of throttling and blocking to show the net neutrality rules were necessary. The agency’s side repeatedly argued that its transparency requirements were an effective way to protect consumers.

The court may be tied up with the case for a long time. Still, even if its participants were using the language of a highly technical legal dispute, the face-off was one of the more dramatic moments so far in the battle over net neutrality.

“Today we fought for an open and free internet that puts consumers first,” Mozilla chief operating officer Denelle Dixon said in a statement. “Mozilla took on this challenge because we believe the FCC needs to follow the rules like everyone else.” The FCC, the statement said, had decided to “renounce its responsibility to protect consumers on a whim.”

“The U.S. Supreme Court has already affirmed the FCC’s authority to classify broadband as a Title I information service,” FCC chief of staff Matthew Berry said in a statement, “and after today’s argument we continue to believe that the judiciary will uphold the FCC’s decision to return to that regulatory framework under which the Internet flourished prior to 2015 and is continuing to thrive today.”

FCC Commissioner Jessica Rosenworcel, who voted against the decision to repeal net neutrality rules, said in a tweet that there was “no shortage of complex issues in oral argument,” but that “the court now has a chance to right what the FCC got wrong” with its decision. “I sat through it all,” she wrote. “I’m hopeful.”

Update, 4:52PM ET: Includes statement from the FCC.