Not necessarily California specific, but more in touristy spots: They're also being let out on AirBnB to short term tourists. It's done a huge number on available housing in many markets. Dublin, for instance, say the long-term rental supply double from August of 2019 to August of 2020 because of all the AirBnB residences looking to keep making money and thus returning to the long-term rental market. Hopefully they'll stay on that market (and more will follow), and AirBnB can disappear.