Yeah that is kind of what I was thinking but I think so far the answers are actually much simpler than what is being presented. So if I had to summarize what I have learned so far it would be something like:

- It is not enough for someone to control a majority of nodes. Entities from the old network would have to migrate since it is a hard fork onto a new network. This could only happen if the bad actor can market a reason for enough entities to exit.

- It is not enough for this to bootstrap the network, because some portion of miners would also have to begin mining on the new network. Same as before, the bad actor would have to market a reason for enough miners to switch and come online.

- None of the above conditions are viable to weaken the old network to the point of significant destabilization where the new network overtakes as the leading network, because you would have to see a mass exit from both entities running nodes and miners onto the new network where the threshold of adoption and hash rate is higher than the old network.

Would that be accurate?

> a hard fork (or new network) is spun up, and the old network is abandoned. 

That is what occurs when there is near universal consensus that the fork is desirable.

When the hard fork is contentious, that fork might not be attempted because otherwise that could mean that some of the hash rate continues using the original (pre-fork) protocol, and some of the hash rate follows the "new" (forked) protocol.  Miners don't want to end up earning coin that is either not spendable or ends up worth less than the coins earned had they mined on the opposing side of the fork.    So there is (or should be) much effort placed by the miners into first determining whether protocol changes are truly universally desired.

If the fork is contentious but pushed ahead regardless, rather than "the old network" getting "abandoned", what you have end up with are two chains, both weaker after the fork (at least, initially).   Bitcoin was harmed (temporarily) by the BCash fork.  BCash was harmed by the BSV fork.  etc.     So it is not in your economic interest to see a fork of your protocol split off into where the original persists and there's also a "new" protocol.   Thus as a miner, you likely won't support adopting a fork of the protocol unless it truly has near universal consensus (and has a near zero chance of resulting in a split of the userbase)

cointastical

Majority of miners wouldn't have to switch - you'd just need mining to happen, and for mining to happen, what you're mining has to be presumed to be valuable.

k00b

I believe I understand. So even in the event that a hard fork happens because of the majority of nodes, what you're saying is this is a new network that the majority of miners would also have to switch to. So in a alternate universe where changing the block size was decided to be a good thing for Bitcoin, what this would actually mean is a hard fork (or new network) is spun up, and the old network is abandoned. In another words, both nodes and miners would have to agree to migrate. Would that be correct?

Cornholio

bitcoin

What happens if an entity operates a majority of Bitcoin nodes?

Well, by changing the consensus among non-mining nodes, you'd accept blocks with different rules, but without miners, your chain wouldn't progress.

So you'd have to start mining too and you'd be generating forked blocks/coins that no one else values given they aren't participating in your network.