Kind of "out there" - but the idea has certainly crossed a more than a few people's minds.
If bitcoin were ever deemed a clear and present danger to national security, all bets are off as to what would happen next.
An idea of a cryptocurrency was published a decade before the launch of Bitcoin. Govt had only one way to overcome the idea - to compromise it. After worldwide adoption of Bitcoin a breach can be "leaked" to initiate a collapse of the cryptocurrency. Trust in whatever-coin will be ruined and govt will get a few decades more to find other solution...
...Something like that?
