There is no one-size-fits-all answer to this question, as the best way to stop someone from attacking you on Coin Master will vary depending on the situation. However, some tips to help stop an attack include: being aware of your surroundings and who is around you, having a strong defense so that attackers cannot easily take your coins, and using traps or other defenses to thwart attackers. Additionally, it is important to report any attacks to the game administrators so they can take action against the attacker.