It is quite simple...the regulations of Cirrus and Plus do not allow banks to charge cardholders from outside their country to charge the so-called convenience fee. If you look closely at the fee notices on many US ATM's, they say that us cardholders are subject to a fee etc.

Now I have heard of some Canadians claiming they used their cards in Texas and were charged the fee. This is contrary to Cirrus and Plus regs; but perhaps the way around it is that the regional network has a reciprocal agreement with the Canadian bank. For example, the company X alliance is a shared teller network independent of Cirrus and Plus (examples are Star, NYCE which are not found in Europe but may be found in Canada, I don't know). So you place your card in a Texas machine and rather than having the transaction routed via Cirrus or Plus (you get no choice in this matter), the bank routes the transaction via another network and thus pinches you for the charge.

But again since these regional networks do not operate in Europe, be assured that using a US issued ATM or debit card in Europe will incur no fees on the part of the European bank. Whatever you pay is determined by your bank period.