Blizzard ToU says "Blizzard has the right to obtain certain identification information about your computer: HDD, CPU, IPs, OS, RAM, VGA card"
They probably have a database where they store this information. Let's say I have 2 wow accounts both using IP masks and I'm using them on the same comp. One is heavy botting/sending gold to the other one who is crafting. Probably bizz will figure things out, if they catch one and figure the fake ip then will ban both or they will know there's the same person using the accounts and again, ban both. Or they could ban all the accounts that use the comp (you know the way blizzard bans ppl... doh!)
So my question to hackers around here is: how to deal with such thing? How to hide that info?