Normally I would call the vendor in question directly, but I did that the first time my credit card was compromised. I was told it was not them, then watched as many others posted online that their cards were compromised. My card was used only once in the past year, for a Botcon purchase. Thinking they must have gotten their act together, I recently ordered Over Run/Runabout. Different card, now this one is compromised. Not cool, especially when their reaction has been to send club members emails because people complained that they should contact folks directly, and proceeded to lecture in said email about how to safely use your card online.
My tip, avoid giving Fun Publications your credit card info.