Yes, Amazon protested Macmillan's eBook policy changes by the temporary Macmillan boycott. But don't forget what Amazon was protesting: Macmillan was refusing to sell eBooks to Amazon at the higher pre-Apple wholesale price that permitted Amazon to set its own price downstream.

Let me say that again. Macmillan demanded that Amazon pay them less money per eBook so that Macmillan could control the price Amazon charged the end consumer. That sounds obviously anti-competitive to me.