I've picked up a few... in recent memory... I picked up a young guy between Mojave and Ridgecrest. The desert is dangerously hot so I felt compelled to stop. Turns out, the kid was just out of jail and on his way home.
I've picked up most in-between Walker Pass and Onyx. The Pacific Coast Trail runs right through Walker Pass. Most of these hitch-hikers have been walkers on the PCT and at this point they are a month or so into a 4-5 month walk. They are usually looking for a ride to or from the local store so they can stock up on supplies. In my experience, PCT walkers have always been fascinating and worth giving a lift.
The last hikers I picked up were in June. They left a nice entry in their
trail journal.