Banned - banned on postcount - http://www.postcount.net/forum/showthread.php?151429-Lako-is-official-a-thief-(With-proof)
There really isn't any rule for messaging someone to ask if they would like to buy an account. I myself get annoyed by seeing messages pop up asking if I want to buy X account. But, not much I can do except say I am not interested. Also, if it really gets excessive with a user, just report the user for it.