For many of these sites, that definition of "going nuclear" would already be them giving up, or at least fundamentally changing. Google blocking sites that they disagree with politically would (and should) be protested by all of us, yet that's exactly what this would be.
I would be concerned about any of these services using their platforms to promote political agendas (especially those with dominant positions). Do it once and you become a Murdoch or one of the many other media barons.
