Formatting does not wipe the info from your hard drive. When they say "wipe", they mean "overwrite" since the data can only exist as 1's or 0's. Although I don't have the reference in front of me, I think the govt. standard is to overwrite with all 1's, then again with all 0's. Repeat this process a couple of times and then followup with an overwrite of random 1's & 0's.