In the real world (at least in the US), the 5th Amendment to the Constitution states, "No person shall ... be deprived of life, liberty, or property, without due process of law; nor shall private property be taken for public use, without just compensation." A host of jurisprudence has determined what the government is, and is not, allowed to do affecting property owned by private citizens. With an announcement from Linden Labs that the Teen Grid in Second Life will be shutting down on Dec. 31, a number of users are discovering that there's no such protection in a privately owned virtual world.
According to this article, those who have invested in developing content and educational tools for use in Second Life Teen are faced with the question of whether to transfer to another platform or give up using the tools they've developed. The situation illustrates the catch-22 facing those who want to invest significant time, energy and resources into developing virtual world real estate when the owner of the platform has the right to take away that real estate without compensating the members of the community for "taking" their property rights in the virtual world away.
As discussed further in this post, Linden Research Inc. and its CEO Philip Rosedale have already been named as defendants in a class action lawsuit relating to the ownership status of virtual property in Second Life. Interestingly, the home page for Teen Second Life still includes, "Click here for a FREE Lifetime Basic account." It isn't clear what Linden plans to do with all of its teen members, since Second Life includes more adult interactions and content and currently requires users to be over 18. The Teen Second Life page also still advertises the monthly rental pricing for virtual land on the Teen Second Life grid.