Authors are upset with publishers who are pricing digitial (e.g. Kindle) editions of their work near hardcopy levels.
It gets worse: Amazon users, availing themselves of that website's "tagging" feature tag overpriced digital editions with the word "BOYCOTT."
And so, some blameless authors (using Amazon's tag search feature) find their work at the top of Amazon's boycott list.
Have a look at this post, including the comments.