I don't get this: how did the alleged attacker know that she was Jewish? Did I miss something?

"Jessica Felber, 20, said that over a year ago, she was holding a sign on campus which read "Israel wants Peace" when another UC Berkeley student, Husam Zakharia, the leader of the Students for Justice in Palestine intentionally rammed a shopping cart into her.  Felber, who filed a suit in San Francisco Superior Court earlier this month, claims she was assaulted because she is Jewish, the SF Weekly reported."