Edan On
Senior at Beverly Hills High School.
The young man sporting the white mask and a white hoodie in widely shared video clips is Edan On, a local 18-year-old high school senior, his mother Sharon On-Siboni confirmed to CNN, though she later said he denies being at UCLA.

Video shows On joining the counterprotesters while waving a long white pole. At one point, he strikes a pro-Palestinian protester with the pole, and appears to continue to strike him even when he was down, as fellow counterprotesters piled on.
“Edan went to bully the Palestinian students in the tents at UCLA and played the song that they played to the Nukhba terrorists in prison!” his mother boasted in Hebrew on Facebook, referencing Hamas. She circled an image of him that had been broadcast on the local news.

“He is all over the news channels,” his mother wrote in a now-deleted post.
https://www.cnn.com/2024/05/16/us/ucla-student-protests-counterprotesters-invs/index.html
An image from Fox 11 Los Angeles posted on Facebook by Sharon On-Siboni shows her son, Edan On, with a white hoodie throwing an object into the encampment created by pro-Palestinian protesters at UCLA. On-Siboni highlighted the image. From Fox 11