3694
BBC News notes that security researcher Chris Vickery uncovered vulnerabilities in Topps databases back in December of 2015 and June of 2016 , but he was n't able to get a response from the company by email .
 ( discover vulnerability: uncovered,  in December of 2015 and June of 2016: time, vulnerabilities: vulnerability, Topps databases: vulnerable system, security researcher Chris Vickery: discoverer) 
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: uncovered,  in December of 2015 and June of 2016: time, vulnerabilities: vulnerability, Topps databases: vulnerable system, security researcher Chris Vickery: discoverer) 