Hmm you bring up a good point here. Does this go in favor of regulation of cryptos or would it be possible to punish someone or a group for performing a 51% attack?
Is it possible to find the bad actor in the case of something like this? My guess would be it depends on the privacy of the coin and a host of other things.
I think it is unethical and wrong, but I’m not sure if it is illegal. If they are breaking a law of some sort they should be punished