It'd be FANTASTIC if the NSA used Amazon's private keys. It'd leak tons of information and cause a huge backlash. Amazon's CA would instantly be revoked. It'd cause a ton of damage to them. That might spur tech companies to spend even more on buying politicians, which is probably a good thing (or a lesser evil).

The CA system is not great. But state actors using a CA is sorta far-down on the list of issues because it is so detectable and provable. CAs take a lot of work to get going and burning a CA isn't something anyone would do lightly. (Well except incompetent ones, like CNNIC.)