The American Civil Liberties Union believes the lawsuit is the first in the country over a school's ban on the $4 bracelets, which are designed to raise breast-cancer awareness among young people. The rubber jewelry has become wildly popular among students, prompting bans across the country.
School officials in Easton argue that the slogan is distracting and demeaning, and that some staff feel it trivializes a serious illness.
The district banned the bracelets in October, a month into the school year and after students had been wearing them without serious incident, the ACLU said.
Kayla Martinez, 12, and Brianna Hawk, 13, had their parents' permission to wear the bracelets but soon found themselves in the principal's office at Easton Area Middle School, the lawsuit states. They were also banned from school dances for a month.
Amy Martinez said her daughter's suspension seems unduly harsh, given that the seventh-grader had agreed to wear the bracelet inside out, with only a breast cancer-awareness website address showing. That, too, was deemed inappropriate under the school dress code, she said.
"I don't believe that vulgarity, obscenity, profanity or nudity (in the school code) apply to the word 'boobies' or 'breast,"' said Martinez, 32, an accountant whose late aunt suffered from breast cancer.
"There were teachers that had 'breast cancer awareness' T-shirts on" in October, National Breast Cancer Awareness Month, she said.
The ACLU calls the bracelets perhaps silly and irreverent, but not lewd or indecent.
The civil-rights group has intervened in similar school disputes across the country, including a second case in Pennsylvania and one in Wyoming in which a student was allowed to keep wearing a bracelet except in the presence of two teachers who found it objectionable.
The Easton families, however, are the first to file suit, ACLU lawyer Mary Catherine Roper said.
"The First Amendment does not allow schools to censor students' speech merely because some students and teachers are offended by the non-vulgar educational message, and silencing the speakers because other students may react inappropriately would amount to a constitutionally impermissible heckler's veto," Roper, who represents the families, wrote in the lawsuit.
"Seeing a bracelet with 'I Love Boobies!' on it is a conversation starter that leads to discussion and awareness of issues affecting young people," the lawsuit said.
The lawsuit was filed Monday in federal court in Philadelphia.
"I am writing from in-school suspension for wearing an 'I love Boobies' bracelet," Brianna Hawk wrote in a recent letter to The Express-Times of Easton. "Even though I am only 13 years old, I am well aware of breast cancer and the effects it has on woman."
Kayla Martinez continues to wear the bracelet to school under her sleeve, her mother said.
The suit asks the district to end the ban, allow the girls to attend all school functions and expunge their disciplinary records. Easton officials did not immediately return phone and e-mail messages seeking comment.
In discussions between the two sides before the lawsuit was filed, district officials complained the bracelets made some people uncomfortable and had prompted some boys to make inappropriate comments, the suit said.
"I don't know ... why the educators are not equipped to deal with distractions. Why do they have to ban, ban, ban?" Martinez said.
Schools from Florida to California have banned the bracelets. One Oregon high school said the message was getting lost on the ninth-grade boys who were wearing them.
The rubber jewelry is sold by the Carlsbad, Calif.-based nonprofit Keep A Breast Foundation to raise awareness and funds for breast cancer organizations.