Officials at Penn State published an open letter this week about an incident that has brought the university under scrutiny once more.

Members of the university's Chi Omega sorority chapter celebrated Halloween at a Mexican-themed party. They wore sombreros and ponchos and pasted fake mustaches on their faces. They held signs that said: "Will mow lawn for weed + beer." Another sign said: "I don't cut grass. I smoke it."

Then they took a photo and posted it online. Outrage spread over the insensitive nature of the photo. Some said it perpetrated stereotypes and were culturally insensitive. Latino students on the Penn State campus demanded a direct apology from Chi Omega, which issued a statement of regret to the college newspaper.

The university president, the president of the board of trustees and other officials expressed their own feelings of deep disappointment.

"How any constituent groups or individuals in the university could behave with such insensitivity or unawareness is a question we must both ask and answer," they said in a letter Thursday.

"Our university is a place of learning and discovery, and there certainly are lessons to be relearned, or even discovered for the first time, from these incidents," the letter said. "The simplest of those lessons is that costumes that include blackface, or that parody or imitate a person or groups of people, are always offensive to someone. They convey either a lack of awareness about the human condition and human sensitivities or, worse yet, disdain for the thoughts, feelings, histories and experiences of others. They suggest a failure to empathize or even a failure to think. They make all of us small."

The incident comes in the wake of this year's conviction of former Penn State assistant football coach Jerry Sandusky for sexually abusing 10 boys over a period of 15 years. He was sentenced to a minimum of 30 years in prison. The scandal led to the dismissal of legendary head coach Joe Paterno, who died only weeks later, and severe NCAA penalties against the school's storied football program.

Reaction to the Chi Omega story, however, has not all been of dismay or outrage.

Some CNN.com readers commented that the picture was just plain old college fun. "Anyone who is offended by this needs to take a pill," said one reader.

Two people who identified themselves as Latino wrote on CNN's Facebook page:

"As a Hispanic-American, I don't find it "offensive" at all," wrote Will Jiminez. "Just a bunch of college kids having fun, if it was offensive I would have cut my wrist every time Family Guy made a joke like this. Kids having fun, that's all! If you're actually offended by this, you're an idiot!!!!

And Adrian Briones said: "I'm Mexican-American myself and I think this pic was just meant to be funny/harmless. The media just trying to make this an issue, like everything else."

But fun doesn't necessarily mean there's no insensitivity, said sociologist David Pilgrim, a specialist on diversity and race relations.

"The two are not mutually exclusive," he said.

When he heard about the Penn State incident, Pilgrim was reminded of a Martin Luther King party held at Tarleton State University in Texas at which attendees showed up in Afro wigs and gang apparel and ate fried chicken and watermelon. One woman even dressed as Aunt Jemima.

"At those parties you don't typically have the people being caricatured in attendance," said Pilgrim, who is also the curator of the Jim Crow Museum of racist artifacts at Ferris State University in Michigan. "That means you have created a safe space in which to defame them."

But is it inherently wrong to wear clothing associated with a racial or ethnic group?

"No," said Pilgrim. "This is why I would say: Ask them what they did at the party."

Did they change the way they spoke or the way they walked? Did they perform a brown-face minstrel show?

"I, obviously, think that's wrong," Pilgrim said.