The attackers allegedly include graduates from Sacred Heart Cathedral, one of the city's oldest and best-known private schools.
The attack happens outside the home of two prominent San Francisco police officers -- former mayoral bodyguard Reno Rapagnani, now retired, and his wife, Leanna Dawydiak -- who were both accused and later cleared of leaking internal SFPD personnel documents during the Fajitagate debacle.
As if that weren't enough, the dean of Yale College has weighed in, as has one of the victim's fathers, Sharyar Aziz -- a prominent New York banker whose son's jaw was busted in two places. He has not only called the mayor's office and police chief -- he's also retained the law firm Gonzalez (as in former mayoral candidate Matt Gonzalez) and Leigh to keep the heat on the cops and make sure "the individuals behind this heinous assault (are) apprehended."
As Rapagnani tells it, his 19-year-old daughter was hosting a New Year's Eve party at the family's Richmond District home for the Baker's Dozen, who were in town as part of a West Coast tour.
The 16 singers showed up late to the party wearing preppy sport jackets and ties, and launched into "The Star-Spangled Banner."
A couple of uninvited guests started mocking them, and allegedly the words "faggot" and "homo" were tossed -- and so were a couple of punches.
The loud noise drew relatives from next door, who promptly ordered the house cleared.
The Yale kids, most of whom were staying with a family a block away, began heading home.
But witnesses said one of the uninvited guests -- who happens to be the son of a prominent Pacific Heights family -- pulled out his cell phone and said, "I'm 20 deep. My boys are coming."
According to Rapagnani and others, the Yale kids barely made it around the corner when they were intercepted by a van full of young men.
"They were surrounded, then tripped -- and when they were on the ground, they were kicked," Rapagnani said.
According to police reports, the cops arrived about 12:40 a.m. to find 20 people fighting in the street.
To the police, who were out in force to keep a lid on New Year's, it looked like just another drunken brawl.
But according to Rapagnani, "This was not a fight -- it was an attack."
Four of the alleged assailants were detained at the scene, then released after the cops took their names.
Meanwhile, Sharyar Aziz Jr. was taken by paramedics to San Francisco General Hospital, and later had to undergo reconstructive surgery in New York for a broken jaw that will remain wired shut for eight weeks.
Another unidentified Yale student sought treatment for a concussion, and a third for a swollen ankle and other abrasions.
Yale Dean Peter Salovey told the school paper that he was "shocked and appalled" by the incident, which has yet to yield an arrest.
Police spokesman Sgt. Neville Gittens said the investigation was continuing and that more people still needed to be interviewed.
Now authorities want the Yale students -- who have left San Francisco and will soon be back in school -- to return to the city to identify their attackers.
But dad Aziz said arranging their return won't be easy.
"The kids are scared s -- less of coming back to San Francisco,'' he said. "I'm just really frustrated.''