It sounds like you’re referencing a specific type of Google search operator ( allintext: , filetype:log , etc.) used to look for exposed .log files that might contain usernames and passwords — with facebook as a keyword.
.log files containing login attempts, error logs, or API debug data./var/log publicly, use .htaccess or robots.txt to block indexing).(also known as Google Hacking). This technique uses advanced search operators to find sensitive information that has been accidentally indexed by Google. Review of the Query Components allintext username filetype log password.log facebook
However, accessing or using the data found through such queries is illegal in many jurisdictions under "unauthorized access" laws. Beyond the legal risk, there is a security risk It sounds like you’re referencing a specific type