Munroe's posts drew national attention in 2011, and because of them, district administrators allowed students to opt out of her classes at Central Bucks East.
The judgment is one of the first court decisions involving public employees and their online comments about the workplace, according to Mary-Rose Papandrea, a professor at Boston College Law School.
"Public employees who blog about their work do so at their own peril," Papandrea said. "There's no guarantee that any speech about the workplace will be protected."
In court filings, Central Bucks contended it didn't fire Munroe over her blog but over poor performance. Rufe didn't tackle that issue, instead answering only whether Munroe's postings constituted protected speech in the first place.
Rufe wrote that Munroe's blog focused mainly on her personal life, sometimes mentioning unnamed students, their parents, and coworkers at Central Bucks East. But Munroe rarely addressed issues of greater public concern that are typically protected in free-speech cases involving teachers, such as a proposed tax increase or academic integrity, the judge said.
"Far from implicating larger discussions of educational reform, pedagogical methods, or specific school policies," Rufe wrote, Munroe "mostly complained about the failure of her students to live up to her expectations, and focused on negative interactions between herself and her students."
Rufe added that Munroe's blog "was sufficiently disruptive so as to diminish any legitimate interest in its expression, and thus her expression was not protected."
Sharon M. O'Donnell, the attorney who handled the case for Central Bucks' insurance company, declined to comment. Steve Rovner, Munroe's attorney, told The Inquirer on Tuesday that she will appeal the case.
"We respectfully disagree with the judge," Rovner said. "The appellate court will have the chance to decide on the free-speech issue."
In her lawsuit, Munroe argued that she meant for her blog, which she wrote under the moniker "Natalie M," to be anonymous. It did not name her school, students, or colleagues but included her photo. She often blogged about her children, the movies she liked, and yoga class. But she also wrote posts about her students, including one that said: "My students are out of control. They are rude, disengaged, lazy whiners."
In 2011, her blog drew attention within the district through social media before attracting news organizations. The district suspended her before reinstating her months later, citing her legal right to work. But the district allowed students to opt out of her classes.
Munroe has claimed that the district then barred her requests to transfer to one of its two other high schools and punished her with overly critical job evaluations before firing her in 2012.
Munroe's suit sought her reinstatement, plus compensatory and punitive damages.
Papandrea, the law professor, said most situations like the one in Central Bucks don't end in court. And she expects future court decisions on similar cases will vary depending on their context.
Papandrea said such litigation could have a chilling effect on public employees who want to speak out about their workplace. And those that do should be careful, making sure their focus is on a broader public interest.
But, she added, "I would advise anyone to not blog about work if they're a government employee. It's just not smart."