[throwanem]

It's not generally speaking a matter of law, since the context is that of a US-based private company moderating the behavior of its voluntary users, and we generally treat this in a very laissez-faire fashion by default. The extent to which Facebook heeds the laws of those countries other than the US, in which it does business and would like to continue doing so, is determined almost entirely by the value it places on that business.

Of course, this situation changes in any such case as new legislation is made to address perceived or actual need, but that hasn't really happened yet here. The same is not true of, say, refusing trade to members of a specific ethnic group because of that ethnicity - a case in which laws of the sort I describe have indeed been made.

(And, to be clear, I have serious qualms with pretty much every facet of the way in which Facebook does business, from its content moderation choices, to the fashion in which it monetizes its userbase, to the extent to which the scale of userbase it's deliberately developed - in support of that questionable style of monetization - might make "voluntary" an inaccurate way to describe the choice people have of whether or not to participate there. My description above is not normative, but positive, and should be regarded as such.)