🔴 2017 — "this is my passphrase"
A Bitcoin brain wallet with passphrase "this is my passphrase" was drained of $2.3 million within hours of being posted online. The passphrase was too simple and easily cracked.
🔴 2015 — Correct Horse Battery Staple
The famous XKCD comic passphrase "correct horse battery staple" was used as a brain wallet. Despite being 4 random words, it was cracked and drained in under 24 hours because it was well-known.
🔴 2018 — Shakespeare Quotes
Multiple brain wallets using Shakespeare quotes ("to be or not to be", "all the world's a stage") were systematically drained. Attackers used quote databases to brute-force these wallets.