Hey @dreemsteem! Thanks for your reply and also thanks for the tip! I didn't know there is a tip bot! 👍I'm happy that you liked my post. In general, you're right: Immutability and vulnerability are contradictory. What I described in my 51% Attack post is the theoretical possibility of an attack. Mostly to change the current blocks / immediate future, which allows the attacker to double spend coins. My post also showed how/why this is a rather theoretical attack, especially if we consider today's situation. The reward of such an attack is just too small in regards to the huge risk/investment that needs to be taken. So why bother to execute a highly risky and expensive attack when one could make a fortune being honest. Things get even trickier if one would want to change the past. I hope my explanation helped a bit! 🙂
Have a great day!