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Cloudflare ’s inspection of tens of thousands of pages that were leaked from its reverse - proxy servers and cached by search engines revealed a " large number " of instances of internal Cloudflare cookies and headers .
 pages: victim; tens of thousands: number of victim; its reverse - proxy servers: victim
Given event type and trigger, please tell me the arguments of all the listed option. Output format is "name1: role1; name2: role2". 
Event type: data breach 
  Option: victim, attacker, attack pattern, purpose, damage amount, tool, time, place, number of victim, compromised data, number of data 
Text: {0} 
Answer:
 pages: victim; tens of thousands: number of victim; its reverse - proxy servers: victim