Scams aren't unique to just the Internet; they've been going on for centuries. One of the most common types is the 419 scam.
I'm sure you've seen the most famous version of this scam at some point. It often involves a Nigerian prince - or royalty of another nationality - trying to move billions of dollars out of his country and offering you a substantial cut to help.
On the surface it sounds laughable, but more than 100,000 people fall for it every year in the U.S. alone.
Many people think the "Nigerian prince" angle is the reason 419 scams are often called "Nigerian scams." That's only part of it, though.
A lot of the scammers you find online are actually based in Nigeria. In fact, the "419" in 419 scams actually refers to the section of the Nigerian Criminal Code dealing with fraud.
So it was no surprise when a study from George Mason University showed that more than half of the scammers pulling a particularly sneaky version of the 419 scam on classified site Craigslist were from Nigeria. What was surprising, though, was the number of scammers involved.
Given that the Internet makes it possible for anyone anywhere in the world to be scammer, would you believe that the scams come from just five gangs in Nigeria? It's true.
The researchers posted "honeypot" ads for laptops - priced, on average, at a 10% premium over Amazon in order to weed out most legitimate buyers. In fact, only one non-scammer tried to purchase an overpriced gadget.
The honeypot started attracting flies and the "buyers" got in touch via email. The researchers responded by sending images of the products.
When the scammers clicked on the image link, their IP addresses, and therefore their location, were revealed.
The good news from this is that if authorities can shut down these gangs, the number of scams online will drop off substantially - for a while at least. Of course, the type of scam the gangs use will still be around.
In fact, you'll probably run into the scam if you try to sell anything online, so here's how it works and how to stay safe.
The version of the 419 scam that the gangs tried using on the researchers was the advanced fee fraud scam. This is when the "buyer" sends you a check that's more than the cost of the item.
The buyer than asks you to deposit it but send back the difference, or send the difference to someone else that's going to pick up the item for them. Of course, the check is fake, which means you're really sending the scammer your own money.
In a really scary twist, the researchers found that the fake checks were so well made any bank would take them without a second thought. So don't think you can stay safe by examining the check.
That's why if you're selling anything online - like your old phone - you should deal locally and in cash. Or you need to use a payment intermediary like PayPal that has fraud protection.
Related scam alert: Foreign scammers use U.S.-based accomplices called "mules" to send the checks, receive the money and move it out of the country. Many of these mules are law-abiding citizens who are also being scammed.
Often the mule answered a "too good to be true" posting on an online job board. If you're looking for a job online, learn how to find online jobs that aren't scams.