Theft of what exactly? Each fork is as valid as any other fork, the challenge is in agreement.

You should really be careful with how you play with definitions, as that will lead down to a slippery slope. Remember that time when someone managed to generate 184 billion bitcoin? With your reasoning, we can now say that the succeeding hard-fork to 'fix' the issue by slashing the bitcoins was theft.

> Remember that time when someone managed to generate 184 billion bitcoin?

you're being intellectually dishonest or even outright manipulative here.

there were never 184 billion coins created on bitcoin chain, there was a bug in validation logic of bitcoin client that made it follow the chain that was invalid.

are you seriously trying to compare that to stealing coins from somebody on a valid chain?

really?

> are you seriously trying to compare that to stealing coins from somebody on a valid chain?

They're not stealing coins from someone on a valid chain, they are forking away to another chain and slashing the user's stake. The user will still have all their coins on "their" chain and it's up to everyone else to decide which chain is "the right one". If the 51% user is truly malicious, the majority of network participants will move away to the new chain, rendering the 51% user's tokens (near) worthless.

> If the 51% user is truly malicious, the majority of network participants will move away to the new chain, rendering the 51% user's tokens (near) worthless.

so being successful is punished by destroying all wealth of the richest participant in the network? nice.

No, being malicious is.

having lots of money is malicious?

No, it's not, that's why I said

> If the 51% user is truly malicious

Having 51% doesn't automatically make you a malicious user. People also wouldn't move away to another chain simply because someone or some group owns 51%. They would move if said person or group abuses the power they get from owning a majority.

Now you've really tangled yourself in a big web.