The dispute stems from several suits against Warner-Lambert over its diabetes drug Rezulin. Warner-Lambert is now owned by Pfizer. The Supreme Court split 4-4 in the case, with Chief Justice John Roberts not participating.

The users of the drug are relying on a Michigan law to allege that the pharmaceutical company engaged in fraud by misleading federal regulators to get the drug approved. The Michigan law shields pharmaceutical companies from product liability lawsuits, unless they committed fraud.

At issue in the case is whether that fraud exception, which allows lawsuits to proceed, is pre-empted by federal regulation of the pharmaceutical industry.

The 2nd U.S. Circuit Court of Appeals in New York ruled that the exception to the Michigan law was not pre-empted by federal regulations, enabling the plaintiffs to pursue the case.

Twenty-seven Michigan residents say they suffered personal injuries caused by Rezulin, a drug that federal regulators approved despite risks to the liver and cardiovascular system.

The dispute over a Burlington, Conn., teenager's Internet journal gave rise on Tuesday to a wide-ranging and contentious federal court hearing about free speech, whether schools can regulate students' language off campus and how the Internet blurs the boundaries of a school campus.

Avery Doninger, the 17-year-old high school senior at the center of the case, sat in the front row as a three-judge panel of the U.S. 2nd Circuit Court of Appeals lobbed questions at the attorneys. Lawyers for both sides described the hearing as uncharacteristically lengthy and suggested that the duration underscored the case's position in new legal territory.

In simplest terms, the hearing Tuesday addressed whether Doninger should be allowed to serve as senior class secretary at Lewis S. Mills High School and, as a class officer, speak at her graduation.

The principal had barred Doninger from serving on the student council because of derogatory comments she made about school officials in an Internet blog. A lower court judge denied an injunction that would have allowed her back on the council.

U.S. District Court Judge Mark Kravitz ruled in August that Doninger had not shown a "substantial likelihood" that she would succeed in challenging the constitutional validity of her principal's decision.

The appeals court did not rule Tuesday, but the judges raised questions ranging from the specifics of the high school's student council election procedures to how the Internet changes students' rights to free speech.

The attorneys staked out opposite positions on the free-speech question.

Asked whether schools should be allowed to regulate anything students write on the Internet, Doninger's attorney, Jon L. Schoenhorn, argued that the Internet should not give schools more cause to regulate off-campus speech. "It's just a bigger soapbox," he said.

The school officials' attorney, Thomas R. Gerarde, argued that the Internet has fundamentally changed students' ability to communicate, allowing them to reach hundreds of people at a time. If a student leader makes offensive comments about the school on the Internet, the school should have the right to act, said Gerarde, who represents Mills Principal Karissa Niehoff and former Region 10 Superintendent Paula Schwartz. "We shouldn't be required to just swallow it," he said.

Doninger's case began with a dispute about the school's annual Jamfest, a battle-of-the-bands-type program that Doninger had helped coordinate. Frustrated that Jamfest was not going ahead as scheduled, Doninger wrote on her livejournal.com weblog that "Jamfest is canceled due to the douchbags [sic] in central office." She also encouraged others to write or call Schwartz "to piss her off more," and included an e-mail her mother wrote as an example.

In fact, Jamfest wasn't canceled and was rescheduled. After administrators found the blog entry, about two weeks after Doninger wrote it, Niehoff told Doninger to apologize to Schwartz, show her mother the blog entry and remove herself from seeking re-election as class secretary.

Doninger agreed to the first two, but refused to withdraw her candidacy. Administrators did not allow her to run, though enough students wrote her name on the ballot that she won. She was not allowed to serve.

In his August ruling, Kravitz suggested that while Doninger wrote her blog entry off school grounds, she could be punished for it because the blog addressed school issues and was likely to be read by other students.

The issue of on-campus and off-campus speech was a key theme Tuesday as attorneys and judges grappled with how the existing legal framework for school-speech issues applies to the Internet.

Student-speech issues have long been governed by a 1969 U.S. Supreme Court case. It established that disruptive conduct by students is not constitutionally protected, but that schools can prohibit expression only if they can show that not doing so would interfere with schoolwork or discipline.

A 1986 Supreme Court ruling added another cause for schools to regulate speech, allowing them to prohibit "vulgar and lewd" speech if it would undermine the school's basic educational mission.

But those cases involved speech that took place on school grounds or during a school activity.

Much of the discussion Tuesday involved another 2nd Circuit Court of Appeals case, Wisniewski v. Board of Education of the Weedsport Central School District in New York. A student was suspended after he created an instant-messaging icon, visible to his friends, that suggested his English teacher should be shot. The court upheld the suspension last year, saying it was reasonable to expect that the icon would come to the attention of school authorities and could create a risk of substantial disruption to the school environment.

Gerarde, the school officials' attorney, argued that the Wisniewski case extended the boundaries of school discretion to the Internet and allowed Lewis Mills to sanction Doninger's blog, which he said was as potentially disruptive as the Wisniewski case.

Doninger's post caused administrators to receive numerous telephone calls and e-mails — including offensive ones, according to court records — and prompted students to consider staging a sit-in. That forced Schwartz to disrupt a presentation she had been scheduled to make to a visiting Chinese delegation.

Gerarde said speech off campus can affect the school. But Judge Sonia Sotomayor challenged his argument, noting that "Pedagogical rights can't supersede the rights of students off campus to have First Amendment rights."

Schoenhorn, Doninger's attorney, offered a different interpretation of the Wisniewski case. The suspension was allowed in that case not because the Internet could be considered on-campus, but because the student's behavior clearly created a risk of disruption, something the school would be able to regulate under the 1969 Supreme Court ruling. In Doninger's case, he said, there was no similar risk of disruption, particularly by the time administrators found the blog post.

The judges asked several questions about the implications of each attorney's views on schools' regulating Internet speech.

"If students are free to say offensive things about administrators on their home computers, chaos will rule," Judge Loretta Preska told Schoenhorn.

They already say offensive things about their teachers, Schoenhorn replied, noting that whole websites are devoted to rating teachers.

Sotomayor asked Gerarde how far school regulation of Internet speech could go. What if a student made false and offensive posts about the mayor and then wanted to run for student council, he asked. Would a principal be able to bar the student from running because she had not shown good citizenship?

Gerarde said it would depend on how likely it was that the school administration would see the blog. But Sotomayor said that would suggest the consequences would be related to how active a student was.

Gerarde posed another situation: What if a class president drove a mile off campus and e-mailed vulgar comments about the principal to hundreds of students? Should the student be able to say he's off campus and the school can't do anything about it? "That's wrong," Gerarde said.

If vulgar speech relates to the school or a public event, the school should be able to regulate it, Gerarde said.