It seems they have all kinds of algorithms to combat fraud, but none of them can be explained in the user agreement, so you end up with all these weird seemingly-arbitrary restrictions imposed on your activity. Pisses me off too. I wish they'd just say "You can only use credit card if you're away from home and buying a TV from a seller in Timbuktu, and you can only use your paypal balance if you're buying a camera from ebay and you've had two password failures in the last three days, and you can't use paypal at all if we don't like your political affiliation".
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