> tell exchanges not to redeem cash

Try telling it to Chinese, Russian, Indian exchanges.

Also... I dunno about India (I think of it as a dysfunctional democracy) but China and Russia are notorious authoritarian economies that people want to take money out of and that's a big part of the global money laundering problem. You might have a problem that your money is in Bitcoin but turn it into Rubles or Yuan and now you have another problem.

What if it is the Chinese or Russian or Indian governments you're worried about? None of those have a libertarian attitude, even if they think it's cool to thumb their nose at Uncle Sam from time to time.