Under pressure from US government and exercising their rights as a private firm, Amazon caved and stopped hosting Wikileaks. Even if it is their legal right to do this, a company like Amazon should take a stand for free speech. Also, they should provide all parties the right to access and continued service, provided that they do not publish anything illegally or going against universal values.
Amazon was never going to be liable for hosting Wikileaks. At most, if the US legal system acted as a puppet for the Executive branch, they would order a Cease and Desist. Only then would a move like the one recently pulled by Amazon be justified but not before that.
Echoeing the now famous tweet by Assange: “If Amazon are so uncomfortable with the first amendment, they should get out of the business of selling books.”