
this search often have great potential for document grinding, which we’ll explore
in more detail in Chapter 10.The file extensions used in this search were
selected very carefully. First, www.filext.com (one of the Internet’s best resources
for all known file extensions) was consulted to obtain a list of every known file
extension. Each entry in the list of over 8000 file extensions was converted into a
Google query using the filetype operator. For example, if we wanted to search for
the PDF extension, we might use a query like filetype:PDF PDF to get the
number of known results on the Internet.This type of Google query was per-
formed for each and every kno ...