Is this acceptable?

I kill a warlock who is fighting a mob - He is about 2 or 3 levels lower than me.
He then logs on an alliance character and whispers me threats about how is going to enjoy camping me yada yada.
He then whispers me again a little time later and says "watch out I'm coming"
He admits that he is using the account to find the area I am in and then brings his 60 to gank me.
How is deemed as acceptable?
He then logs on an alliance character and whispers me threats about how is going to enjoy camping me yada yada.
He then whispers me again a little time later and says "watch out I'm coming"
He admits that he is using the account to find the area I am in and then brings his 60 to gank me.
How is deemed as acceptable?