What may be crystal clear to most turns out to be shockingly unclear to thousands of other Americans every year.

Indeed, at least $100 million worth of not obvious.

That's how much the U.S. Secret Service estimates gets swindled away annually through those sketchy e-mails offering to share small fortunes - but only for those helping to move the money out of some besieged African country.

The scam is classic pigeon drop: They've got upwards of $15 million they need to move from Nigeria, Zimbabwe, South Africa or Sudan. And they can't do it on their own, but need your bank account to do it.

But as soon as you give them access to your accounts and funds - and perhaps some upfront fees or "good faith" payment - they'll disappear.

Volume fuels success

Chances are, you've gotten something similar. (One such offer appeared in my e-mailbox just since I started writing this column.)

That they are so prolific has always surprised me - probably because offering something for nothing seems such an obvious scam. But then it hit me: They exist because they succeed.

"There's still a certain percentage of people who will respond for whatever reason - be it gullibility, be it greed," said Jim Emery, special agent in charge of the Cincinnati field office of the U.S. Secret Service.

Victims come from every background, educational level and profession, he said. Each loses around $10,000 to $15,000.

"Their success rate comes from volume," he added. "There are untold number of appeals, and if just one person bites, that's a success."

Officially, the scam is called the Nigerian Advance Fee Fraud because it was started decades ago via snail mail in Nigeria. But now that is mostly a misnomer, Emery said, because the technology of e-mail gives the scammers geographic flexibility as well as spamming volume.

Investigations have shown the e-mails to now originate from anywhere in the world, including the United States.

Cases harder to solve

But the cases are getting increasingly difficult to investigate - partly because of technology, partly because of politics.

"They use technology to their advantage," Emery said. "People are adept at masking their identities, never staying in one place at one time."

Also, the priorities of the Secret Service might be shifting.

Once part of the Department of the Treasury and charged with investigating financial fraud, the agency is now part of the Department of Homeland Security. How individual financial fraud fits into protecting the country's critical infrastructure and systems still is unclear.

But the investigations likely won't be necessary once the e-mails stop being successful; once recipients stop responding to them.

"Ignore them," Emery said. "Treat them as spam, junk mail, and trash them."

Contact Amy Higgins at 768-8373; ahiggins@enquirer.com; or 312 Elm St., Cincinnati 45202. She regrets that she cannot reply to all individual questions.