The Challenge of Choosing a Commencement Speaker THE actor James Franco at U.C.L.A. John M. McHugh, the former Army secretary, at the State University of New York at Oswego. The commentator Ben Stein at the University of Vermont. All are notable figures who were invited to participate in college graduations in recent years, only to withdraw or be disinvited in the face of campus protests. Commencement season has arrived, and with it a perennial debate over free speech on campus. So far this year, students on at least 10 campuses have protested speakers invited to commencement events. Robert B. Zoellick, the former president of the World Bank, withdrew last month as a commencement speaker at Swarthmore College - his alma mater - after students mounted a campaign on Facebook calling him an "architect of the Iraq war" and a "war criminal" because of his support of the 2003 invasion. Benjamin Carson, a renowned neurosurgeon and conservative icon, dropped out as a commencement speaker last month at Johns Hopkins University after students protested comments he'd made lumping together homosexuality, pedophilia and bestiality. Earlier this month, President Obama was the subject of a controversy at Morehouse College, where he is slated to give this year's commencement speech. Morehouse also invited a Philadelphia pastor, the Rev. Kevin Johnson, to speak the day before Mr. Obama. But after the minister wrote a column in The Philadelphia Tribune criticizing Mr. Obama for failing to appoint African-Americans to cabinet positions, the university told Mr. Johnson - in a move that alumni later criticized - that they wanted to provide a broad spectrum of views so he would not be the sole speaker at that event. Mr. Johnson publicly withdrew as a speaker. Even though most free-speech advocacy groups do not compile data on such protests, "It does appear that "disinvitation season" incidents have accelerated in recent years, with this year inspiring an uptick of these episodes," said Greg Lukianoff, president of the Foundation for Individual Rights in Education. In the era of Facebook and flash mobs, university administrators appear to be more skittish, knowing how quickly ideas - be they good, bad or just plain unruly - can go viral. "It's difficult for an institution to identify speakers who don't raise the ire of some group but can still provide a thought-provoking commencement speech," said Rae Goldsmith, a vice president at the Council for Advancement and Support of Education, an educational association. Some commentators regard student protests against invited speakers as another indicator of the divisiveness of American culture and part of a larger trend of politically correct "orthodoxies" on campuses. Universities are meant to be bastions of open-mindedness and free speech, they say, but are more prone to censoring disagreeable ideas or drowning them out - a practice some have labeled "the heckler's veto." "By giving in to protesters, colleges are denying the majority of students their right to hear controversial opinions and drawing their own conclusions about those opinions," said Bob Beckel, a Democratic strategist and commentator, in a recent USA Today online debate. But other free-speech advocates contend that these protests actually represent an increase in free speech and that students should be able to influence campus decisions. The aim of such protests, these advocates say, is not usually to prevent controversial speakers from presenting their ideas but to encourage them to take the microphone at a time other than commencement day. "This isn't about tolerance or intolerance," Mark Schwartz, a Swarthmore alumnus, told the campus newspaper about the successful protests against Mr. Zoellick's appearance on campus, where he was to receive an honorary degree. It's about whether or not you honor somebody within the highest ideals of Swarthmore's Quaker tradition. The protests take various forms. In 2002, Syracuse students held up their wallets during the commencement speech by Rudolph W. Giuliani, the former mayor of New York City. The wallets were meant to recall Amadou Diallo, an unarmed West African immigrant who was shot 41 times by policemen in 1999 after he reached for his identification. The conservative commentator Ann Coulter canceled an appearance at the University of Ottawa in 2010 after about 2,000 students, angered by her comments about Muslims, crowded the entrance to the hall at which she was scheduled to speak. Some schools have tried to insulate themselves by avoiding civic leaders and politicians, and turning instead to pop culture icons like Kermit the Frog, Dolly Parton and Stephen Colbert for commencement addresses. But even this does not always work: Mr. Franco's invitation from U.C.L.A. was protested for its lack of gravitas. Other universities have reserved the guest speakership for campus figures, like popular professors or university chancellors. According to the Foundation for Individual Rights in Education, more than 70 universities have tried to corral protesters into "free speech zones" - designated places where rallies are permitted but are often removed from main events or in fenced-off areas. Still, the protests show no signs of ebbing. Cuts to education and welfare spending by Gov. Tom Corbett of Pennsylvania spurred an online campaign against his scheduled commencement appearance at Millersville University in central Pennsylvania. And in April, Skidmore College students stormed a faculty meeting to protest an invitation to Cynthia Carroll, the former chief executive of the mining company Anglo American, citing her company's environmental and human rights record. "It's my commencement," one student told faculty members. Not hers. Not yours. Ian Urbina is an investigative reporter for The New York Times.