Montclair (near Los Angeles, not the area in Oakland) recently made it illegal for pedestrians to use their cellphones while crossing an intersection. Montclair is located about 33 miles away from Los Angeles. Honolulu was actually the first city to implement this law not too long ago as well.
The city, which is home to about 36,000 people, said "Pedestrians now account for 15 percent of all vehicle-related fatalities and when compared, 2016 experienced a 22 percent increase in pedestrian fatalities from 2014. An estimated 30 percent of pedestrians engage in distracting activities while crossing the street, which include text messaging, phone calls, listening to music, etc."
If you are caught you can expect to pay $100 for the first violation, up to $200 for the second violation and up to $500 for every violation after. It is probably safer to just look both ways and keep your eyes on the road!