Amazon.com is dropping its online marketing affiliates in North Carolina and Rhode Island. It did so to avoid having to deal with recent sales-tax legislation in Rhode Island and North Carolina. These bills would require Amazon and other companies to collect sales tax for in-state sales if they had any online marketing affiliates in the state. Amazon is disputing the constitutionality of the new provisions. (For a more extensive background discussion, including comments from representatives of the affiliates, see the two linked articles above, from the Wall Street Journal.)
I was curious whether Amazon’s affiliate agreement allowed it to terminate this way. The answer seems to be "yes." I used The Wayback Machine to look up a March 2006 version of the Amazon affiliate agreement. It says in paragraph 12, "Either you or we may terminate this Agreement at any time, with or without cause, by giving the other party written notice of termination." Amazon is probably glad someone on their legal team thought to include that language.