Decentralised Finance (DeFi) may seem a tempting option for those seeking financial gain, autonomy, and self-governance… But how safe is a world in which ‘code is law’? Closer inspection reveals an ecosystem experiencing several hacks, attacks, and fraud. Estimates show at least US$6.5 billion has been stolen since DeFi’s inception, and one particular DeFi feature is often at the centre of this theft – flash loans. Unlimited, ungoverned, and uncollateralised, flash loans give hackers the toolkit to highly leverage their potential attacks. The only cost is the gas fees required to send the transaction. In this blog post we consider the world of flash loans and their criminal counterpart – flash attacks.