If you use a MAC, 600,000 of their users were infected with this trojan which could compromise credit card numbers:
http://www.huffingtonpost.com/2012/0...n_1405766.html
In addition, one must never give their credit card number to any customer service employees. Any one of them could use it improperly. Also, never give your credit card number to 3rd party vendors at Amazon. Those folks could also have their database compromised.
If Amazon did have their database compromised, it would make headlines and we'd all see it in the news.
The solution, in any event, is have the bank issue a new credit card to you and then change the number at Amazon.