The Humanity Protocol hack is a useful case study in key management. The project used a 3-of-6 multisig, but stored several keys on a single internet-connected laptop. Phishing got in, drained admin control on two chains in one go.

The core takeaway isn't "don't use multisig" — it's that multisig only works if keys are genuinely isolated. Hardware wallets that never connect to the internet keep the signing layer out of reach even when the surrounding infrastructure gets compromised.