The distribution of diameters and orbital distances from the parent body of 156 named moons of the planets in the Solar System is not random. All 11 moons with diameters larger than $1\,000\,\mathrm{km}$ are positioned between $400\,000\,\mathrm{km}$ and 4 million km from the parent, whereas the far more numerous small moons are distributed on both sides of this central region and are largely absent from the region in between. This small-satellite ‘exclusion region’ is particularly evident for the gas giants since they have multiple satellites spanning a wide range of distances from the parent. Application of mathematical criteria analogous to those that have been used to help define the ‘gravitational clearing’ of planetary orbits around the Sun suggests that the absence of small satellites in this region around the planets may be a result (atleast in part) of gravitational clearing by the large moons present at these distances from the parent. The most significant exception to the observed diameter-distance distribution—Hyperion, on Saturn—is attributed to its 3:4 orbital resonance with Titan, while other obvious exceptions are the Trojan satellites of Saturn’s moons Tethys and Dione. The smallest satellite diameter that seems necessary for clearing of its ‘sphere of influence’ is around $400\,\mathrm{km}$ .

In the last several decades a diverse movement has emerged that seeks to extend the accountability for human rights beyond governments and states, to businesses. Though the view that business has human rights responsibilities has attracted a great deal of positive attention, this view continues to face many reservations and unresolved questions.

Business ethicists have responded in a twofold manner. First, they have tried to formulate the general terms or frameworks within which the discussion might best proceed. Second, they have sought to answer several questions that these different frameworks pose: A. What are human rights and how justify one’s defence of them?; B. Who is responsible for human rights? What justifies their extension to business?; and C. What are the general features of business’s human rights responsibilities? Are they mandatory or voluntary? How are the specific human rights responsibilities of business to be determined?

Within the limited space of this article, this article seeks to critically examine where the discussion of these issues presently stands and what has been the contribution of business ethicists.

The ever increasing nexus between human rights and business and the accompanying vagueness of concepts such as a company's ‘sphere of responsibility’ for human rights can, and has, created anxiety amongst companies. Considerations of human rights traditionally take place in the context of a state-based system of global governance; however, the rise of the corporation as a powerful non-state actor in recent decades has seen increased interest in understanding the emerging relationship between human rights and business and what, if any, responsibility business should assume for protecting human rights. This article considers the role played by U.S. technology companies such as Yahoo, Google and Microsoft in working with the Chinese government to censor internet content and thus intrude on the human rights to freedom of expression and opinion and the right to privacy. It concludes by focusing on the practicalities of protection and how human rights responsibilities might be apportioned between states and business and if so, how, when and why such an obligation might ensue.

Should companies’ human rights responsibilities arise, in part, from their “leverage”—their ability to influence others’ actions through their relationships? Special Representative John Ruggie rejected this proposition in the United Nations Framework for business and human rights. I argue that leverage is a source of responsibility where there is a morally significant connection between the company and a rights-holder or rights-violator, the company is able to make a contribution to ameliorating the situation, it can do so at modest cost, and the threat to human rights is substantial. In such circumstances companies have a responsibility to exercise leverage even though they did nothing to contribute to the situation. Such responsibility is qualified, not categorical; graduated, not binary; context-specific; practicable; consistent with the social role of business; and not merely a negative responsibility to avoid harm but a positive responsibility to do good.