What does"Wipe free space" in CrapCleaner do? - Yahoo! Answers

What does"Wipe free space" in CrapCleaner do? - Yahoo! Answers: "in the data area. It just modifies the file table to indicate that the file's physical location in the data area is free. Later, the system can use that data area to write another file.

So unless your disk is very new, the free portions of your disk are full of fragments of files your system has modified, deleted or moved. Using disk utilities, you can read out that old information, which may contain all kinds of stuff you wouldn't expect. Anything that was ever on your computer could still be there in the free space, and some of it can be recovered.

Wiping free space means actually erasing the data in the free space. There are several reasons you might want to do that. Basically, anything ever written on your computer could be there in the free space. Anybody could recover that information. If it's in any way sensitive, for instance personal correspondence, business information, credit card numbers, pr0n, it could fall into the wrong hands. (Any hands but yours being the wrong hands.)

So before you hand over a computer to another person, say when you sell it, you should wipe the free space after removing all your files. But remember, even another user with an account on your computer could recover your deleted files. So if you don't trust the other users of your computer, you should also wipe the free space after deleting, modifying or viewing any sensitive information.

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