Your balance is irrelevant - your available credit line is debt, as at any moment you can be liable for up to that amount.
Here (Singapore) card conditions were recently changed so that you would only be liable for the first $100 of fraudulent transactions (assuming you can prove it wasn't you). I think the bank can still hold you liable for more if they find you were negligent about guarding your card details.
Prior to these condition changes, I remember being told by the bank that you would be liable for all charges incurred before you had reported the card physically stolen or lost.
It doesn't. The GP comment is FUD.
So things like car loans and mortgages could be bad, since they start at 100% and go down.