The Supreme Court on Monday rejected an appeal from a Pennsylvania school district that tried to ban students from wearing "I (heart) Boobies!" bracelets to promote breast cancer awareness, ending a case that began more than three years ago with the suspension of two middle-school girls who refused a principal’s order to take them off.

The justices left in place a federal appeals court ruling from August that found the bracelets were not "plainly lewd," nor had they caused a disruption. The lower court sided with two students who sued the Easton Area School District in 2010 with the help of the American Civil Liberties Union.

Easton is one of several school districts around the country to ban the bracelets, which are distributed by the nonprofit Keep A Breast Foundation of Carlsbad, Calif.

"The principle here is that even kids talk about important things, and when they talk about important things, that’s what we should be encouraging," Mary Catherine Roper, an attorney with the ACLU of Pennsylvania, said Monday. "Kids should be able to talk about things that matter to them in language that is both respectful and familiar to them."

The district’s solicitor, John Freund, said he was disappointed the Supreme Court won’t hear the case.

The ruling by the Philadelphia-based 3rd U.S. Circuit Court of Appeals "robs educators and school boards of the ability to strike a reasonable balance between a student’s right to creative expression" and districts’ responsibility to make sure schools are "free from sexual entendre and vulgarity," Freund said.

Groups representing school boards, superintendents and principals had supported Easton’s appeal.

The case started in 2010 when two girls, then ages 12 and 13, challenged the ban. Kayla Martinez and Brianna Hawk said they were trying to promote awareness of the disease at their middle school. They wore the bracelets on their school’s Breast Cancer Awareness Day — in defiance of a ban that had been announced a day earlier — and refused to take them off. The girls filed suit after being suspended from class and banned from attending the winter dance.

"I am happy we won this case, because it’s important that students have the right to stand up for a cause and try to make a difference. We just wanted to raise awareness about breast cancer," Hawk, who was in eighth grade at the time, said in a statement distributed by the ACLU.

Earlier Supreme Court rulings give schools the right to restrict vulgar speech or speech that is likely to cause "substantial disruption." Roper said districts still have that ability.

"In a situation where these bracelets were actually causing problems, school officials could take action," Roper said. "This is all based on a case where they weren’t sparking inappropriate behavior or inappropriate comments. Schools always have the authority to keep order and prevent those things from happening."

Freund predicted the Supreme Court would eventually revisit students’ free-speech rights.

"Unfortunately, it will take more lawsuits, more attorneys’ fees and more chaos in the classroom," he said.