https://www.washingtonpost.com/nation/2020/10/12/california-...
Apparently the state GOP set them up and has admitted as much on Twitter. They say they are justified under California's law that allows ballot harvesting.
They're putting them outside places usually frequented by GOP voters (gun stores, churches, etc) to help make it easier for them to vote.
They may have a pretty solid argument. But more importantly, like most of these types of shenanigans, it probably won't be resolved until after the election.