1965
The hackers also claim that since they 've made their ransom request public a few days ago , others have joined in their effort and shared even more credentials with them , putting the number at more than 750 million .
 ( ransom: made their ransom,  The hackers: attacker) 
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:
 ( ransom: made their ransom,  The hackers: attacker) 