I am scared.

I was just going to log into my wow account on eu.battle.net, i wrote in my account information and then BAM suddenly i was in some strangers account, i have no connection to this person.

I am not friends with this person
He plays on a different server
I have never seen this person before

Why is this happening blizzard? I really don´t want this to happen to my account due to all my auctions and guild control.

Ty
-Gamenta