The law may be fair or unfair, but Amazon could have easily complied, as it does reluctantly for New York. Perhaps Amazon already wanted to get a bunch of affiliates off its books anyways and this provides a good excuse. But the company is just being childish by lashing out in this manner.
At any rate, the business impact of firing the California affiliates is most likely minimal for Amazon, or else it would have hung on to them, as it has been doing with the New York affiliates.
Amazon cuts off California affiliates - San Jose Mercury News.
