Dont Expect Privacy on the Web

Opinion: Whether they realize it or not, many people leave sensitive information out in plain view on Web sites. But sooner or later, a Google search will dig it up.

Theres always more stuff to find on Google. And like all programs, if you actually read the manual, you can do things you didnt even imagine.

A couple of Google features have been sparking interest lately on security mailing lists. Both of the features rely on users leaving sensitive information out where Google can find it.

Once Google knows about it, you can use advanced search features to dig up the information. Its issues such as these that remind me that the weakest security link is usually the one between the users ears.

The first one I saw is the numerical-range search feature. You can search for numbers between a low and high value. For example, a search for "100..199 Madison Ave." will find any instance between "100 Madison Ave." and "199 Madison Ave.," including "156 Madison Ave."

This being the Internet, the next logical step was to search for credit card numbers. Try this one, for "Visa 4366000000000000..4366999999999999".

But dont go rushing off to Amazon.com just yet to rip off the poor schnook in the Google entry. A lot of the numbers you find in entries like this are fake—test data for software developers, for instance. But Im sure some of them are real, too. Somebody was careless with that data.

But the other feature is my favorite. You can search for file by file type, meaning file extension. Want to search for all Adobe Acrobat files containing the phrase "foreign car repair"? Try this link: "foreign car repair" filetype:PDF". Thats about 78 hits there!

Google actually can search 12 non-HTML formats including Microsoft Office, PostScript, Corel WordPerfect, Lotus 1-2-3 and, as we have seen, PDF. And you can mess with the query a little to search simply for a file of a particular type, e.g. "QDF filetype:QDF".

Yes, that will show you Quicken data files that users have helpfully put up on the Web. The vast majority of these appear to be sample files for books and such, but I havent looked at all of them. Id bet there are some real ones.

Next Page: It gets worse.