Just because Apple is on the hook for allegedly anti-competitive book sales doesn't mean that Amazon is above reproach. As promised, groups representing both authors and booksellers are calling on the US Department of Justice to investigate Amazon for antitrust abuses. The Kindle maker is supposedly using its literary dominance to "impoverish the book industry," hurt writers' careers and even limit free expression. For example, the company is known to squeeze publishers who object to its pricing policies by withholding pre-orders and otherwise depriving these 'enemies' of income. There are also concerns that Amazon wrecks rival stores through unfair price dumping (that is, selling below cost) and refuses to carry some authors based purely on their politics or fame.