"We found 20 different files parked on the server, each file with two or three or four, up to 20, profiles. Cumulatively, there were about 300 profiles collected in that one day. And 100 to 200 were mac.com addresses."
NOT GOOD. Ars goes on to rightly point out that Apple customers are typically higher-income, and thus more desirable targets. We'd also add that Apple users are not as accustomed to malware and phishing as our Windows-using friends, but as email and web browsing doesn't care about platform, we REALLY need to be. Just like you wouldn't open a package left at your door that smelled like gasoline and was ticking, even if it came in a Tiffany's box, don't open links or give out credit card information just because it fakes coming from Apple.
REMEMBER: Don’t EVER believe email requests for secure data. Go to the site yourself (not through their link — type it in) and log in and see if there really is a problem. Check domain names carefully. App1e.com isn’t the same as Apple.com, they’re just hoping you don’t notice. Worried about the recent DNS poisoning attacks? Use HTTPS/SSL or use a direct IP address. If in any doubt, pick up a phone and call Apple (or your credit card company) directly.