This was rather predictable. The State of California needs money. They decided to get some of that money from online sales by attempting to tax folks. In particular, they were looking at Amazon. Governor Brown signed legislation that allowed for this.
Amazon, of course, retaliated by shutting down the accounts of all of the California-based affiliates. This is in the neighborhood of 100,000 companies, charities, and individuals.
I do get California's point. They need money and local businesses can't compete with online sales (in part because what makes the online sales cheaper is the lack of sales tax). That being said, Amazon was very specific about what they were going to do if the legislation passed.
As it happens, I am one of those Amazon affiliates and my account has indeed been shut down. In my case, it was a relatively small amount of money per quarter. Still, every little bit helps. However, I know of a number of businesses that are predicated solely on being Amazon affiliates and selling books as an affiliate. I can only imagine what this will do to their ventures.
If it were me, I would be considering a relocation to Nevada. Perhaps ten feet across the border!