I don’t know what I’m more excited by: that someone has successfully executed a 51% attack on a blockchain, or the fact that 51% attack is now a part of the modern vernacular. All joking aside, this is no picnic for the Bitcoin Gold folks, and I honestly don’t know how this ends for them (and it could be…you know…the end).
Bitcoin takes a lot of heat for the amount of power it consumes (roughly equivalent to the power needs of Ireland), but that’s what makes it secure. In other words, it would cost you twice as much power +1% to pervert the Bitcoin blockchain, making it effectively impossible. But Bitcoin Gold is not Bitcoin, and it’s obviously vulnerable to this type of attack. This just adds to the urgency for a viable proof-of-stake solution.