Assuming the total computation power of the swarm is constant, it would take a 100% majority a year to rewrite a law that was passed a year ago. It would also b

Assuming the total computation power of the swarm is constant, it would take a 100% majority a year to rewrite a law that was passed a year ago. It would also be relativly easy to detect (noticing that you just resolved a gigantic fork, or that the law just changed), and easy to prove, as someone with a copy of the old blockchain could still prove it has a years worth of work on it. Once this is done, you can explicitly blacklist the offending chain and get on with life.