I withdrew 100 THB from a Family Mart ATM in Bangkok. There was no prompt to decline DCC as far as I could tell, nor any warning that the ATM would charge a fee. I should have been charged only ~$3 USD, but my Ally Bank activity shows I was charged nearly $9 for this withdrawal. Is this an extreme case of DCC, or a rogue ATM that charges fees without warning? Ally's ATM fee for international withdrawals is usually just 1%.