Late-night rioting has erupted at a succession of United States universities this month. But the protests were not over free speech or US imperialism, but bans on alcohol.
The worst came at Michigan State University, where an estimated 3,000 students, angered by a drinking ban at university football games, threw rocks and bottles at police who fired back with tear gas. There have been smaller eruptions at several other universities over drinking. Earlier this year, the picturesque university city of Boulder, Colorado, was riven by several nights of rioting.
US colleges have progressively tightened their rules on alcohol, following stories of "binge drinking" deaths. Several campuses have banned alcohol altogether, while others strictly enforce the legal drinking age of 21 in most states, using the growing ranks of university police.
Campus police forces are an often overlooked side of US higher education. But for several million students annually, they are the most visible representatives of law and order. Unlike British or European universities, which typically rely on corporate-style security, the campus cops at the US's biggest universities are mostly sworn officers. They have full police powers and routinely carry 9mm handguns that are standard issue for big-city forces.
Campus police forces give university administrators more control of events, and their numbers and resources appear to have grown considerably in recent years. There has been a growing focus on campus security, amid claims that colleges cover up serious crimes, particularly sex crimes. In an era of high competition, US colleges have had to sell themselves to prospective students and parents as safe places. But it is law suits, and the threat of them, that have been a driving force behind more policing.
The early May "ride-along" on the graveyard shift with the campus police of San Diego State University was largely uneventful: just a few traffic tickets, warnings to cyclists and checks on parked cars. For police at the university - one of California's largest, with some 35,000 students and staff - the bread-and-butter beat work is theft.
But after a stop for Starbucks coffee comes the first alcohol arrest - an underage student spotted by an officer carrying a half-drunk bottle of beer. Looking muzzy, the student is shown into the back of the squad car, compounding the offence by presenting someone else's driving licence.
With just 25 sworn officers, San Diego State is less policed than some - the University of California campus in Los Angeles, with a similar student population, has about 75 officers. But SDSU has one of the most prominent chiefs in the country. John Carpenter has travelled the world, from China to South Africa, lecturing and advising on campus security issues.
With 25 years in the trade, he is a past president of the International Association of Campus Police Chiefs. This spring he was in Brussels to talk to European security chiefs.
Several of his officers carry not only holstered 9mms but a back-up handgun. Three of them are expert marksmen, and two squad cars have shotguns in prominent front-seat racks.
It is not such an absurd over-display of force as it may seem. In August 1996, an engineering graduate student at SDSU shot three professors dead during a thesis presentation, apparently blaming them for his academic failures. It was two of Chief Carpenter's officers who confronted the student in the hallway and persuaded him to lay down the gun.
The shooting left many universities jittery about workplace violence, but SDSU in particular. About a month ago, a psychiatrist called out of the blue to report an anonymous message on her answering machine from an alleged student promising to "shoot the hell out of the cafeteria". Discreetly, undercover and uniformed officers staked out the dining area for weeks.
Last year, SDSU police were tipped off that the boyfriend of a student, having already shot and killed a relative, might be on his way to campus. They located his car and established that he was a guest. Astonishingly, as the police converged and began a night-time evacuation of the residence hall, it was other students who called the girl's room and alerted the armed suspect.
This kind of unpredictability is part of the campus job, Chief Carpenter explained. "Once students began to know we were aiming at a certain area, they began to play games because they saw so many police officers outside. You just don't know how they are going to react, what they are going to do."
San Diego State, time and again, has found itself handling a huge media influx. "They are hot on any calls here. Being the major university in a city, whatever happens is a major issue. You can have ten rapes within eight blocks of here, but if you have one rape on campus, it's a major issue," Chief Carpenter said.
University crime brings lawyers as well as the media. Chief Carpenter has been a witness in law suits from Massachusetts to Alaska, where universities have typically paid out large sums to victims' families. In most cases, Chief Carpenter said, universities typically revamp their security in order to guard themselves against other law suits.
Last December, the University of Toledo, Ohio, paid out a reported $1 million settlement to the family of murder victim Melissa Herstrum, who was shot 14 times by a university police officer in an attack that seemed motiveless. The suit alleged that the man had not been psychologically screened.
University life throws up unique situations. At the University of Texas at San Antonio, Chief Ron Seacrist remembers a case from a previous job of a university professor who "was selling grades to young ladies to star in pornographic movies with him".
His department, tipped off by a pornographic video delivered anonymously to the office, tracked down half a dozen women involved. But it was unable to close the case because of its staff's reluctance to testify. The professor was eventually fired on ethics grounds, but he was never charged.
Both of the police chiefs have advice on the issue of alcohol. Figures released in a recent survey by the Chronicle of Higher Education showed that robbery, assault and burglary statistics are stable, but alcohol and drugs violations are up 10 per cent and 5 per cent respectively.
Extra enforcement is probably responsible. "You need to control alcohol and monitor it, but not ban it," Chief Carpenter said. If stricter policies are implemented, it must be tactfully, he said, after consultations with students, particularly now, when the example of rioting has been set. Chief Seacrist notes that what many campus crimes have in common is drink.
But he concedes: "I can remember growing up myself. You could not drink until you were 21, but we all went out and did our drinking at 17 or 18." But if caught, he said, instead of being arrested, "you would probably have been taken home to daddy."