"In many cases, scammers troll the Internet for victims, and spend weeks or months building a relationship," the embassy website says. "Once they have gained their victim's trust, the scammers create a false situation and ask for money. Scammers can be very clever and deceptive, creating sad and believable stories that will make you want to send them money."
According to the embassy, American citizens ask every day for help either retrieving money they already lost or protecting themselves from the hoaxes, which in Nigeria are referred to as 419 scams after the section of the Nigerian criminal code they violate.
On Monday, authorities announced a major victory in that fight. Interpol, the international law enforcement organization, said they'd teamed with a Nigerian financial crime commission to curtail some of the fraud that costs individuals and companies hundreds of millions of dollars each year.
In an operation carried out in Port Harcourt, in southern Nigeria, Interpol arrested a 40-year-old man identified only as "Mike," who is believed to be responsible for a scam network that stole some $60 million from more than a hundred businesses around the world. Another unidentified man, aged 38, was also arrested and is believed to be Mike's accomplice.
Officials said they are just two of some 40 people thought to have worked together on a series of scams, including one where an unidentified target "was conned into payout out $15.4 million," Interpol said in a statement about the arrests on Monday.
The network spanned across at least eight countries, including South Africa, Canada, Malaysia, and the United States.
The suspects involved in this case are accused of running a campaign slightly more sophisticated than those that request strangers wire them money from across the Atlantic Ocean. In some cases, criminals would hack the email addresses of high-level company employees, then use them to request that a lower-level employee send money to a bank account they controlled. In other instances, they would hack a supplying company's email accounts and then send buying companies instructions to send money to one of their accounts.
Although both men have already been released on administrative bail, Monday's arrests could signal a major step forward in combating the networks that have given Nigeria a reputation as one of the largest scam capitals of the world.
And according to the FBI, there are still a lot of people to help, with Americans continuing to fall for emails promising to share a royal fortune with them so long as they provide their bank account information.
"While such an invitation impresses most law-abiding citizens as a laughable hoax, millions of dollars in losses are caused by these schemes annually," the FBI's website says. "Some victims have been lured to Nigeria, where they have been imprisoned against their will along with losing large sums of money."