For what it's worth, I've had several unsuccessful attempts of somebody trying to use my credit card about 3 months ago. They were in the UK, but so am I. I had used this card at SDE 2-3 times max. I had no issues with my previous card though through which I'd been buying all the SDE releases since inception. Obviously not enough to suggest SDE's fault, but I'll be switching to PayPal for future purchases just in case.