In the past fifteen years, the Alien Tort Statute (28 U.S.C. § 1350) has become the leading instrument for the litigation of human rights abuses committed by companies worldwide. It allows non-US citizens to seek damages for violations of international law before U.S. federal courts, regardless of where the alleged wrongdoings took place, as long as the defendant company (or individual) is subject to the personal jurisdiction of the court. To date, about 150 ATS claims against companies have been filed, with only very few actually proceeding to trial. The liability of companies is usually premised on the aiding and abetting of actions committed by state organs. In 2004, the Supreme Court admonished courts to exercise caution in recognizing causes of action under the ATS (Sosa v. Álvarez-Machain, 542 U.S. 692). Since then, the bar for ATS claims has risen substantially. In 2007/2009, the Court of Appeals for the Second Circuit determined the mens rea standard for aiding and abetting to be purpose, and not mere knowledge, to further the principal offense. In a recent decision (Kiobel v. Royal Dutch Petroleum Co., 621 F.3d 111 (2d Cir. 2010)), the same court held that companies can not be sued under the ATS at all, because international (human rights and criminal) law is only addressed to states and individuals; thus, companies are unable to violate it. This article begins with a general introduction to the ATS and the relevant case law (part B). Next, it turns to the jurisdictional requirement of a »violation of the law of nations« (part C. II). The main issue here is whether this violation must be committed by the person being sued (e.g., the company which assisted a state's human rights violations), or whether it can be committed by another person (the state as a principal; a natural person as an organ of the company), for whose actions the defendant is held responsible on other grounds. This is followed by a review of recent case law on aiding and abetting as well as on corporate liability (parts D and E). While the correct mens rea for aiding and abetting would appear to be knowledge rather than purpose, the Second Circuit was right in holding that at present, international law is not directly binding on companies. The article concludes with an assessment of the impact of the Kiobel decision. From the viewpoint of legal policy, it is unfortunate that victims of human rights violations are losing a crucial remedy to seek redress from companies. It is equally regrettable that the development of customary international law towards corporate accountability has suffered a serious setback.