Chain detective ZachXBT reminds users to strengthen account and fund security. It said that Yubico (security key), Proton (mail service) and Tutanota (mail service) are currently offering discounts. Proton supports Bitcoin payments, while Tutanota can use Monero (XMR) to purchase gift cards through its official partner ProxyStore. In addition, some products from hardware wallet brands Trezor and Ledger are also on sale. ZachXBT recommends that users avoid using Gmail or SMS 2FA (two-factor authentication) and switch to security keys or hardware wallets to store funds as soon as possible.