Anyway, I don't think any red flag appropriate here since already tagged. Account already worthless.
Due to various concrete red flags, I believe that anyone dealing with this user has a high risk of losing money. (This flag will only be shown to guests/newbies.)
I think flag type 1 is appropriate here according to its definition. Four dt members have tagged the account but guest will not know unless there is a flag created and supported.
Supporting the flag.