My first account got banned because

#0 - Dec. 17, 2008, 12:49 a.m.
Blizzard Post
A hacker hacked into it, used my account to farm, so blizzard perma suspended it for the reason of "account sharing"

God I love this service of the game, keep up the great work blizz! Keep banning people for getting hacked!!
#32 - Dec. 17, 2008, 8:54 p.m.
Blizzard Post
If you wish to query an account ban, please contact our Account Administration team. The forums, monitored by the Community team, are no the place for this kind of request.

http://www.wow-europe.com/en/support/accountadmin.html