Stolen card details nearly always from American cards as their banks & CC companies are SHIT. However, my chargebacks are low as I usually void the dodgy ones.
Easy to tell if you're vigilant, but some bastards always creep through and they are usually the same ones too
I guess they have a list of stolen CC details?
Out of any genuine chargebacks or refunds, I would probably say Germany is the worst country overall, tight bastards - usually the cheapass ones using debit options.
I get my hosting providor to block obviously bad countries/traffic I have no interest in like Russia, Ukraine, China, India and Vietnam (was a fave for proxies) - let them use proxies than download easier and quicker on their own networks. Fuck em