The scene would be familiar to University of California graduates of a certain age: Protesters filled U.C. Berkeley's Sproul Plaza, clashing with police who beat them back with nightsticks. In the end, campus police arrested 39 protesters after students twice tried to set up an occupation in the plaza. Following Oakland's confrontations with protesters over the last two weeks, police on Berkeley's campus are taking a hard line early on, and it did not go smoothly.

The San Francisco Chronicle reported that police first clashed with protesters in the afternoon, arresting seven, and then again in the evening when they tried once more to set up their tents. The Daily Californian, the campus newspaper, reported 39 total arrests, seven in the afternoon clash and 32 in the much larger demonstration later. The clashes came as thousands of students and faculty filled the campus's central Sproul Plaza as part of a "day of action" on University of California campuses statewide. The Daily Cal reports:

The various protests at UCs, CSUs and a community college involved several marches, demonstrations outside banks and the arrest of 11 UCLA students, according to The Daily Bruin. The largest protests were held at UC Berkeley and UC Irvine,  each attracting more than 1,000 demonstrators.

But Berkeley, true to its roots, saw the most raucous and combative demonstration. This video of police hitting student protesters has already exploded on Twitter:

Cal TV has the confrontation from another angle:

The Chronicle talked to one protester who said the police crackdown was unusual:

Andrew Snyder, 25, a graduate student, was locked in arms with fellow protesters when he said he was "crushed" by police as they pushed toward the tents. He said he was surprised the police acted forcefully twice in one day.

"Police don't usually act violently the first day of a camp going up," he said. "This just shows us how afraid they are of the Occupy movement."

As the day went on and night fell, thousands of students, faculty, and other activists filled Sproul plaza. Protesters from Occupy encampments in Oakland and San Francisco reportedly joined the demonstration. AlterNet's Joshua Holland shared this photo of the crowd on Twitter:

At around 6:30 p.m., U.C. Berkeley Vice-Chancellor Harry Le Grande told the Occupy Cal general assembly they'd be able to stay in the plaza continuously, but they couldn't set up tents, according to the Daily Cal. But somebody did set one up, and protesters squared off with police in front of Sproul Hall to try to defend it. Eventually, police cleared it out after clashing with protesters again, and set up a perimeter around Sproul Hall. The Daily Cal posted this dramatic shot:

By about 2 a.m., most of the crowd had cleared out, but a few protesters did take the university up on its offer to sleep there, as this TwitPic photo from Sacramento Fox News reporter Elissa Harrington shows:

Meanwhile, in Boston, Harvard students stood off with police in Harvard Yard for an Occupy Harvard demonstration. They marched through Cambridge and erected a tent city, shutting down Harvard Yard, according to the Harvard Crimson, but the standoff ended peacefully, without arrests. What with the chaos at Penn State overnight, it seems unrest has started jockeying with the kegger as the evening pastime of choice for college students this semester.