Bitomat, once Poland's largest Bitcoin exchange, accidentally deleted its entire database in 2011, resulting in the loss of 17,000 BTC (worth around $425,000 at the time). The exchange had no backups, leaving users unable to recover their funds. The incident highlighted early cryptocurrency exchange vulnerabilities and the importance of proper security measures. Bitomat's collapse contributed to growing awareness of custodial risks in the crypto space. Today, the lost Bitcoin would be valued at over $1 billion.