I suspect that after a decade or more of "Nigerian Scam" emails, the majority of which earlier seemed to originate in Nigeria and involve persons with apparently Nigerian names and involved in Nigerian government or businesses, the OP and most other FTers would be likely to blame fraudulently ticket purchasers/travelers from Lagos to IAH (or anywhere else) on Nigerians.

Reinforcing that conclusion might well be based on the events of the last few weeks during which the Nigerian government and military have displayed an almost unimaginable level of ineptitude and an inability to act or react to the current situation there. Prejudice is often the product of perception.