For those unfamiliar with California fruit vendors, allow me to describe them.
Imagine a NYC street hot dog cart, except it's an insulated ice chest instead of a steamer. On top is a plexiglass box with more ice and various peeled fruit on display. Atop this is usually an umbrella for shade.
You don't buy bulk fruit to take home. You have one choice: the number of servings you want. The vendor cuts up a variety of fruit into bite sized chunks (usually pineapple, coconut, mango, papaya, etc.) gives it a squirt of lime juice and optionally a dash of cayenne. It's served in a plastic bag and eaten with a disposable fork. It usually costs four or five dollars a serving. It's one of my wife's favorite treats.
Here in LA County, they're not regulated by the police but by the Department of Health - the same folks who inspect restaurants. (The police will politely ignore you if you call them to complain about a fruit vendor. And the Sheriff will rudely ignore you.) And AFAIK they're technically forbidden. Just like the bacon-wrapped hot dog vendors, the only time you see them is after 5pm on Fridays and on weekends when the Health Department inspectors are off duty.
It's a traditionally Hispanic practice, but you can find them in most parts of town. They generally set up on the verge between the sidewalk and the curb, in well-trafficked areas, usually in mixed-use or commercial zoned areas. I've never seen one on a purely residential street.