[lmm]

Not really - what's the attack? You could maybe somehow clone a card with a balance on it and spend that balance twice, if you can figure out that a particular terminal is offline (or have a way to take it offline), but how do you turn that into an attack that you can scale enough to cover the fixed costs? You're not getting your own terminal without a contract and due diligence on your company, so you can't really pull off an attack that needs to control both sides.