Fraternities have long been a fixture of American college life, but revelations about sexual assault and racism are casting a pall over hard-partying "Greek life" on campus.
Some are going so far as to question the future of fraternities, an institution that dates back to the earliest days of the United States.
"This is the biggest outcry I have seen in the past 50 years," Laura Hamilton, a sociology professor at the University of California at Merced, told AFP.
In recent weeks, several fraternity chapters have been suspended or dissolved at a pace the Chronicle of Higher Education newspaper has described as "an unusually rapid clip."
Video of racist chants by members of the Sigma Alpha Epsilon chapter at the University of Oklahoma touched off a national furor with their reference to lynching and use of the N-word.
The chapter was promptly shuttered and two students expelled.
The Penn State chapter of Kappa Delta Rho has been suspended for a year as police investigate a private Facebook page featuring images of naked and unconscious women who attended its parties.
And the Sigma Alpha Mu fraternity at the University of Michigan has been suspended after its members were involved in vandalizing a ski resort, wrecking 44 rooms at an estimated cost of more than $400,000.
Booze-infused frat parties and hazing rituals that morph into sexual assault, accidents and even death have turned up regularly in US news media over the years.
Claims of a gang rape at the University of Virginia, reported in Rolling Stone magazine, were later discredited, yet fueled a nationwide debate about sexual assault on American campuses.
With their own, often historic premises, fraternities "generally have a monopoly on alcohol consumption for those under 21," said Hamilton, who studies the sociology of university life.
Over the years, they have "reinvented themselves as fun sort of party houses," with no policing of what goes on within their doors, she said.
Hollywood has perpetuated the image with movies like the 1978 hit "Animal House" starring the late John Belushi and, more recently, the Seth Rogen and Zac Efron vehicle "Neighbors," about a frat house that turns a quiet neighborhood upside down.
"Greek life" harks back to 1776, when Phi Beta Kappa -- which means "philosophy is the guide to life" -- was founded as a forum for discussion at the College of William and Mary in Virginia.
"Fraternities exist on college campuses to create opportunities of friendship and brotherhood, leadership, academic success, and philanthropy and community service," said Peter Smithhisler, president of the North-American Interfraternity Conference.
Fraternities are male-only, but "not specific to race or religion," said Smithhisler, whose group represents 5,500 chapters at 800 US and Canadian campuses, making up a total of 350,000 freshmen.
"Each organization chooses their membership based on a core set of values" as well as academic and community involvement standards, he said.
Fraternity membership can have long-term career benefits: most Supreme Court justices, senators, cabinet members and Fortune 500 executives were frat men, as well as 18 US presidents since 1877.
Students who run afoul of their fraternity's honor code can expect "appropriate disciplinary action," said Smithhisler, who praised the way national fraternity leaders acted "swifted and decisively" in the Oklahoma and Penn State cases.
To each their own
African-American fraternities have existed since 1906, and all-female sororities since 1851. Upstarts cater to Latinos, Asians and gays.
But it is predominantly white fraternities that are able to "garner benefits" from the university system, including access to social and economic capital, said Rashawn Ray, a sociologist at the University of Maryland at College Park.
With their own premises, they can "control social environments, reduce the involvement of authority figures, maintain privacy and choose when to be viable and invisible," he said.
Hollywood star Will Ferrell, whose 2003 comedy "Old School" centered on three friends trying to revive their frat-house glory days, said the Oklahoma incident makes "a real argument" for ditching the fraternity system altogether.
"Because when you break it down, it really is about creating cliques and clubs and being exclusionary," said the actor, a Delta Tau Delta member during his University of Southern California student days.