hedwards: Which is fine as long as you're not concerned with the effects of drop box wide deduplication and the security implication that has on your data.
johnki: I actually wasn't aware of that, but even so, it's usually nothing sensitive that I'm passing through Dropbox, so it works for me personally.
As long as you have things backed up elsewhere, the worst case scenario is where they can overwrite a file with one that has a matching checksum.
With system-wide dedupe the likelihood of that is insignificant. With the number of files that Dropbox has, it's still probably insignificant, but much more likely.
Personally, I wouldn't necessarily worry too much about it. You shouldn't be storing anything sensitive there anyways as the staff has access to all that data.
I'd be more concerned about losing a file due to somebody acquiring a computer with the dropbox install still active, or sitting down and deleting things out of that folder as I don't think Dropbox puts any effort at all into worrying about that.
But, I think that last point is pretty much any provider of such a service, not Dropbox specific.