You can extract some unextracted private info from Google Search. This is usually for gathering information from the target, named footprinting. This information comes public accidentally.
intitle: "webcamxp 5"
filetype:env "DB_PASSWORD"
site:starbucks.com
site:starbucks.com inurl:admin
site:starbucks.com intext:admin
site:starbacks.com intitle:login
site:starbucks.com filetype:pdf
"authentication failure; logname=" filetype:log
filetype:reg reg HKEY_CURRENT_USER username
intitle:"Nessus Scan Report" "This file was generated by Nessus"
allinurl:tsweb/default.htm
For more commands, Google Hacking Database can give more examples.
It is an information-gathering tool to scrape up emails, subdomains, hosts, employee names, open ports, and banners from different public sources like popular search engines, PGP key servers, and the Shodan database.
theHarvester -d starbucks.com -b google # email,ip,domain
theHarvester -d starbucks.com -b netcraft # subdomain,host