Attention: Battle.net security breach

[Mavfin]

I think a large majority of Blizzard hacking victims use the same password on other websites, and when THOSE websites get hacked, their B.net account is a casualty.

Just for the uninitiated: I work in IT security for a 15K-student regional community college, and I see lists by the thousands a couple times a week of email/password pairs from various websites. We just grep through them for any of our local domain emails to keep an eye on compromises here, but, we might find one or two of ours out of four thousand or ten thousand on the list. This is why you don't want to share email/bnet passwords with other passwords around the internet.

I know people have heard that this happens, but you have to see the scale and frequency of these lists to truly understand the problem.