Kraken cryptocurrency exchange, and CertiK, a blockchain security firm. Kraken enlisted CertiK's help to address a vulnerability, but CertiK's white-hat hackers inadvertently triggered an alert misinterpreted as an extortion attempt. This misunderstanding was quickly clarified, highlighting the critical need for clear communication in cybersecurity operations. The incident underscores the importance of cooperation and proper protocol in managing security vulnerabilities.