Many of the Nigerian '419's' use the identities of organisations like Central Bank of Nigeria and NNPC...as both are our customers we usually pass on the letter to them.
The perpetrators can be easily traced via their phone numbers which they always seem to provide...most now are amateurs who have heard that it used to work, the pro '419er's' have moved on to other things...
Usually the same day they get a visit from 20 armed NPF police...I still get a real kick out of going along and watching the raid with the 'chaps' being dragged out and cuffed...and handled oh so roughly as well!