Self-styled anti-fascist rioters brought their violence back to Berkeley this weekend, attacking peaceful demonstrators attending a "Rally Against Hate" with sticks and smoke bombs. On Monday, conservative author Ben Shapiro, who's slated to address students in a lecture at the University of California, Berkeley on Sept. 14, issued a stern warning to anyone who may be spoiling for a fight over his appearance.

In a nine-post thread on Twitter, Shapiro challenged Berkeley to prove its stated commitment to "free speech" by directing the university police force to "do their jobs and stop violence." The Berkeley campus police have faced sharp criticism for following "stand-down" orders that prevent officers from intervening in violent protests so long as there is no threat of imminent death, allowing riots to break out without intercession from law enforcement.

Young America's Foundation, the conservative nonprofit that sponsors Shapiro's campus lectures, is suing Berkeley for First and Fourteenth Amendment violations over its decision to cancel Ann Coulter's lecture on campus last spring. The school's absurd stand-down order is noted in that lawsuit.

Here are seven parts of Shapiro's thread, edited without numbers marking each post for Twitter users:

1. Berkeley has agreed to host us. They say they support free speech.
2. They required us to pay a $15K security fee.
3. That means the police should damn well do their jobs and stop violence. No excuses.
4. ATTENDEES, DO NOT SHOW UP FOR VIOLENCE.
5. If the police refuse to do their jobs, or are told not to be administration or government figures, Congress should act.
6. Those who engage in political violence break the covenant of civilized society. The police must enforce that covenant.
7. The alt-right is repulsive. Antifa is repulsive. We should all stand together against political violence. Join us, Berkeley.

After linking to the lecture's official website, Shapiro concluded, "I hope to see everyone there for a civilized discussions about issues. If you're there for violence, stay home or be arrested."

The $15,000 security fee, along with Shapiro's honorarium and private security costs for the event, are being paid by YAF. Universities love slapping conservative student groups with onerous "security fees" for lectures to pressure them out of hosting the event and disincentivize them from hiring speakers in the future. It's an old tactic that essentially amounts to a tax on conservative speech.

Shapiro's call for Congress to act in the instance that Berkeley police, having pocketed $15,000 from a nonprofit student group, fail to actually secure students is also notable. The bestselling author testified himself before Congress last month, detailing his experiences with violence and censorship on the campus lecture circuit in recent years.

Berkeley was thrust into the spotlight last school year after riots forced the university to cancel Milo Yiannopoulos' lecture. Later in the spring, Berkeley made headlines again for canceling Coulter's lecture. In the early planning stages of Shapiro's upcoming lecture, YAF (my previous employer), announced the school attempted to block the event by claiming there were no available rooms. Upon receiving an onslaught of negative media attention, administrators somehow managed to find one.

After the dramatic incidents that played out during the last school year, the university finds itself at the center of a high-profile national conversation about campus censorship. This event will mark the first real challenge of the 2017-2018 school year.

It's difficult to find a person who does a better job at communicating mainstream conservative values to college students than Shapiro. If Berkeley is wise, administrators will do everything in their power to protect his lecture and prove the school values the intellectual contribution conservatives like Shapiro make to the political discourse.

The ball is in their court.

Emily Jashinsky is a commentary writer for the Washington Examiner.