Well he wasn't customer but playing major role in directing the...

Well he wasn't customer but playing major role in directing the operations of the criminal syndicate.... I don't think, exchanges can control who is who & why is he/she is buying or selling crypto currency

Following from the smh news link
"The man is suspected of playing a major role in directing the operations of the criminal syndicate which used various dark net sites, bitcoin accounts and legitimate business for the sourcing, payment and distribution of the illicit drugs, police said."