Have you ever mistyped the address of a web site and received a message like "Error - page name could not be found" or "The page you requested: page name does not exist"? Certainly you have, and odds are you never gave it a second thought; you simply corrected the address or went to a different site altogether. It happens all the time. There are plenty of dead links, or links with typos to stumble upon. However, when you encounter an error message like the two listed above, you are actually witnessing a potential security breach - not necessarily against the site, but rather against you directly.
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