1890
They thanked Tavis and others like him for reporting these sort of problems and helping them make online security even better for the rest of their users .
 ( discover vulnerability: reporting,  others like him: discoverer, Tavis: discoverer, these sort of problems: vulnerability) 
Locate the role in the text that participated in the event based on the event type and return it in the event list. 
 Option: Event type: phishing, data breach, ransom, discover vulnerability, patch vulnerability, Arguments type: vulnerable system, capabilities, vulnerability, number of victim, issues addressed, compromised data, damage amount, common vulnerabilities and exposures, victim, patch number, number of data, tool, discoverer, time, purpose, place, payment method, releaser, vulnerable system version, attacker, supported platform, patch, price, vulnerable system owner, trusted entity, attack pattern. 
Text: {0} 
Answer:
 ( discover vulnerability: reporting,  others like him: discoverer, Tavis: discoverer, these sort of problems: vulnerability) 