The headline above would, if some readers had their way, include a "trigger warning"—a disclaimer to alert you that this article contains potentially traumatic subject matter. Such warnings, which are most commonly applied to discussions about rape, sexual abuse, and mental illness, have appeared on message boards since the early days of the Web. Some consider them an irksome tic of the blogosphere’s most hypersensitive fringes, and yet they've spread from feminist forums and social media to sites as large as the The Huffington Post. Now, the trigger warning is gaining momentum beyond the Internet—at some of the nation's most prestigious universities.

Last week, student leaders at the University of California, Santa Barbara, passed a resolution urging officials to institute mandatory trigger warnings on class syllabi. Professors who present "content that may trigger the onset of symptoms of Post-Traumatic Stress Disorder" would be required to issue advance alerts and allow students to skip those classes. According to UCSB newspaper The Daily Nexus, Bailey Loverin, the student who sponsored the proposal, decided to push the issue after attending a class in which she “felt forced” to sit through a film that featured an “insinuation” of sexual assault and a graphic depiction of rape. A victim of sexual abuse, she did not want to remain in the room, but she feared she would only draw attention to herself by walking out.

On college campuses across the country, a growing number of students are demanding trigger warnings on class content. Many instructors are obliging with alerts in handouts and before presentations, even emailing notes of caution ahead of class. At Scripps College, lecturers give warnings before presenting a core curriculum class, the “Histories of the Present: Violence," although some have questioned the value of such alerts when students are still required to attend class. Oberlin College has published an official document on triggers, advising faculty members to "be aware of racism, classism, sexism, heterosexism, cissexism, ableism, and other issues of privilege and oppression," to remove triggering material when it doesn't "directly" contribute to learning goals and "strongly consider" developing a policy to make "triggering material" optional. Chinua Achebe's Things Fall Apart, it states, is a novel that may "trigger readers who have experienced racism, colonialism, religious persecution, violence, suicide and more." Warnings have been proposed even for books long considered suitable material for high-schoolers: Last month, a Rutgers University sophomore suggested that an alert for F. Scott Fitzgerald's The Great Gatsby say, "TW: suicide, domestic abuse and graphic violence."

What began as a way of moderating Internet forums for the vulnerable and mentally ill now threatens to define public discussion both online and off. The trigger warning signals not only the growing precautionary approach to words and ideas in the university, but a wider cultural hypersensitivity to harm and a paranoia about giving offense. And yet, for all the debate about the warnings on campuses and on the Internet, few are grappling with the ramifications for society as a whole.

Not everyone seems to agree on what the trigger warning is, let alone how it should be applied. Initially, trigger warnings were used in self-help and feminist forums to help readers who might have post traumatic stress disorder to avoid graphic content that might cause painful memories, flashbacks, or panic attacks. Some websites, like Bodies Under Siege, a self-injury support message board, developed systems of adding abbreviated topic tags—from SI (self injury) to ED (eating disorders)—to particularly explicit posts. As the Internet grew, warnings became more popular, and critics began to question their use. In 2010, Susannah Breslin wrote in True/Slant that feminists were applying the term "like a Southern cook applies Pam cooking spray to an overused nonstick frying pan"—prompting Feministing to call her a "certifiable asshole," and Jezebel to lament that the debate has "been totally clouded by ridiculous inflammatory rhetoric."