Proposition 2, as it's called, required eggs in California to come from chickens that have enough room to fully extend their limbs and turn around freely. It was a direct challenge to the egg industry, because most egg-laying chickens can't do that in standard henhouses, where they live in small cages, five or 10 birds to a cage.
http://www.npr.org/blogs/thesalt/2014/12/29/373802858/how-californias-new-rules-are-scrambling-the-egg-industry