Many people publish data on web servers without realizing the security risks of such publication. This makes Google and other search engines tools for hackers seeking sensitive information. Google comes with some advanced features to allow web surfers to fine-tune their searches. The "site:" operator restricts searches to certain servers, websites, and top level domains; the "intitle:" operator restricts searches to webpages with certain words in the title; and "filetype:" allows searchers to look for common file formats, such as Word documents, Excel spreadsheets, and Adobe PDF (Portable Document Format). Black hat hackers can use these feature to dig up sensitive information, such as Excel budget sheets with names and contact information of valuable clients or plain text password files. The author recommends several sites administrators can consult to learn how to protect sensitive files from malicious Google searches.
http://www.securityfocus.com/columnists/224

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