It proves the device was loaded by the owner of that private key. That individual can accept accountability for whatever materials exist on that device, indemnifying whatever vendor sells or makes available the device (i.e. a library).
If content on the device isn't properly attributed or is non-free used without permission, then governments can investigate the owner of that private key in reliable faith that that individual distributed that content unless their private key was stolen.
I'm not supporting that copyright should exist even as an option to those who would like to restrict the yields of their creative efforts, however the economic reality we face includes a lack of social infrastructure for libre artists to mass-distribute the yields of their efforts as well as for individuals to calculate their fiscal honor-obligation to these artists. When talking about these kinds of large scales over-paying artists remains a real possibility with negative consequences all around (including to the artist [consider how winning the lottery affects many in poverty] ). I don't think I'd be the first to suppose that Star Citizen was "too" successful in their fundraising, and feeling an obligation to develop the game quickly hiring too much help, too quickly diluting their original vision. Rigorous attribution enables libre support models: without it, one can only blindly support and hope artistic yields come about. Besides that, transitions to libre support must ensue gradually and old models can't immediately drop out of existence. While artists transition someone needs to accommodate both toxic copyright models as well as healthy libre models. <b><i>One does not simply get a smoker to stop smoking by depriving them of smokes.</b></i>
This necessary infrastructure should add up to retailers getting used to the idea of facilitating donations.