In an email sent out to its California-based affiliates, has said it will stop working with them after a new state law was passed that forces online retailers to collect sales tax in the state.

California Governor Jerry Brown signed the bill into law on Wednesday as part of a larger budget package.

In its email, called the bill “unconstitutional and counterproductive.”

Amazon’s affiliates are individuals or companies that run websites referring visitors to Amazon and then they get a cut of any resulting sales.

California is just the latest state to pass this type of legislation, which is expected to net $200 million annually.