Okay good find unless there are no exceptional explanation from the users like: they are brother, sister or friends etc.
There are no such explanations, he is a serial scamer. You can check his
trust (and see other banned alts there) or read
here.
Not sure what to do. Do we tag them or admin/mod will ban them?
By the way, what I am sure about is that - this is a reputation topic.
He is already tagged by DT members. I created this topic to attract attention about the situation with the ban - he continues to conduct his "business" on the forum and evades the ban.