IfIn the unlikely event that an attacker manages to flood the mempool with so many of his own addresses that he ends up owning all of the addresses in the priority list of an output that he also owns, despite random selection, he can try to double spend it. If he cosigns themhis transactions before he publishes them, they will be invalid and not even propagate. He must publish his signed transactions before he can cosign them, so everyone can see them. As soon as he cosigns one, the others are invalidated. If he cosigns more than one, he merely locks up his coins until he resolves the conflict, either by redacting all but one transaction, or by using one of the other addresses on his list to cosign just one of them. All that work for nothing because he only earns the fee cosigning other user's transactions.

If an attacker manages to flood the mempool with so many of his own addresses that he ends up owning all of the addresses in the priority list of an output that he also owns, despite random selection, he can attempttry to double spend it. If he cosigns them before he publishes them, they will be invalid and not even propagate. He must publish his signed transactions before he can cosign them, so everyone can see them. As soon as he cosigns one, the others are invalidated. If he cosigns more than one, he merely locks up his coins until he resolves the conflict, either by redacting all but one transaction, or by using one of the other addresses on his list to cosign just one of them.

If an attacker manages to flood the mempool with so many of his own addresses that he ends up owning all of the addresses in the priority list of an output that he also owns, despite random selection, he can attempt to double spend it. If he cosigns them before he publishes them, they will be invalid and not even propagate. He must publish his signed transactions before he can cosign them, so everyone can see them. As soon as he cosigns one, the others are invalidated. If he cosigns more than one, he merely locks up his coins until he resolves the conflict, either by redacting all but one transaction, or by using one of the other addresses on his list to cosign just one of them.

If an attacker manages to flood the mempool with so many of his own addresses that he ends up owning all of the addresses in the priority list of an output that he also owns, despite random selection, he can attempt to double spend it. If cosigns them before he publishes them, they will be invalid and not even propagate. He must publish his signed transactions before he can cosign them, so everyone can see them. As soon as he cosigns one, the others are invalidated. If he cosigns more than one, he merely locks up his coins until he resolves the conflict, either by redacting all but one transaction, or by using one of the other addresses on his list to cosign just one of them.