Data disposal: Every action leaves a trace

I am wondering whether this is much ado about nothing. While I understand that deleting files isn't as simple as just dragging them to the recycle bin, it seems to me that the theoretical possibility of retrieving data has been exaggerated.

Every action leaves a trace, as the article's title says. The dreadful data I've stored on my hard drive makes its mark, leaves its traces. So do all the other things I store on that disk, even in the same location as the secret data. While *theoretically* it might be possible to reconstruct my secrets from a careful analysis of the magnetic domains, I have yet to see anyone actually accomplish this after a couple of overwrites. Perhaps it *has* been done, but if so, I haven't seen it.

Sure, the various ghosts of the data may remain, but how can you distinguish the faded images from one another?

Assuming it's possible, how practical would it be to reconstruct the data? How much time and effort (= money) would it be worth to get hold of it? Short of serious criminal investigations or national security, there probably aren't many good reasons to try to reconstruct deleted data.

I would think that the problem isn't at all that data can be reconstructed from properly deleted files, but that so often these files are *not* deleted properly.