In the past few days, due to the weak random number issue with Coldcard wallets, thefts have escalated to 1,367.05 BTC, involving 4,585 wallets. This is yet another reminder for BTC holders: don’t underestimate the importance of a Passphrase. A Passphrase is like the '13th/25th mnemonic word'—an additional layer of independent protection beyond the 12/24 mnemonic words. Even if, in the future, some unforeseen issue (like random number vulnerabilities) leads to mnemonic leaks, without the Passphrase, attackers still cannot directly access the assets in your wallet. For a higher level of security, consider: ◦ Setting an independent Passphrase and remembering it ◦ Using multi-signature wallets ◦ Participating in entropy generation yourself The security boundary of Bitcoin ultimately depends on every step of private key generation and management.