A Prius driver who was using his cell phone to record footage of a pack of motorcyclists veered into them Sunday morning, prompting some of the bikers to beat him up on a San Mateo County freeway, the California Highway Patrol reported.

The incident unfolded just after 8 a.m. as several motorcycle clubs cruised on Harley-Davidsons and other bikes in the fast lane of northbound Highway 101 near Belmont, between Ralston Avenue and West Hillsdale Boulevard.