Can't say I'm a big fan of this feature. Theoretically it could be useful in PRSI when somebody tries to deny that they ever said something, but beyond that... Do I really want every instance where I corrected a misspelling, replaced an adjective with a better one, or moved a few words around, on record? Even in PRSI I don't really see the point. People there have fast eyes and long memories, so it really isn't likely you can get away with deleting your words and then denying you ever said them, unless you really did it immediately. And that, I think, can be forgiven. We've all written something a little rash and then immediately changed or deleted it.