Definitely true
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And only 10 passes? Spybot allows unlimited number of passes, and you can do it to a file while its in use and running. Causes havoc to your system afterward, but the file is gone
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I like to keep a couple of virus scanners, but really, if I am doing anything risky, I usually use a virtual machine to do it. There are currently very few viruses that can jump out of an isolated virtual machine. To properly isolate a VM, just put it on a different subnet and don't give it access to any network shares you may have. This way the isolation is hardware controlled.