World of Warcraft Merge-Hacker

The World of Warcraft Merge-Hackers hack you WoW account by, as the name says, merging it into a Battle.net account.
They mostly do this between Friday past 8pm and Sunday evening, because that’s when the Blizzard help-line is closed. So you can’t call them directly for help.
You know you’re hacked when you get an e-mail from Blizzard (real mail) saying that you’re account has been merged successfully into “random e-mail address”. Which isn’t your own, and you can’t find out which one it is either because it gives the address like this: H***@hotmail.com for example.
Best thing is to way until Monday morning, 10am, and call to the free Blizzard account help-line. (see site for number) They’ll ask you for your account name, name, real e-mail address and personal question, if you answer these correctly, they’ll put you on hold for a few minutes. At least an hour after you called you should get an e-mail saying your account has been unmerged and containing a random password.

In the next 4 days a Game Master will look on your account and mail all lost items back to you.

(e-mailing Blizzard is also possible, but this takes 5-7 days for reply)

How to prevent from being merge-hacked?

You best check your computer each several days for viruses, spyware or malware. If you notice problems with you usual scanners, free download a new one, and check with it. (viruses or malware sometimes corrupt the scanner itself so they become invisible)
Merge your account yourself into you own Battle.net account.
If you get fake WoW-mails, don’t click on any link in there, just by loading the page a virus could enter you system.
Change your password regularly. (so if it’s a Blizzard leak, they won’t be able to hack you after some time they found it)