"Men," said he, "must have corrupted nature a little, for they were not born wolves, and they have become wolves." —Voltaire, Candide

One of the less pleasant aspects of our online Age of Anxiety is that most of us now get anonymous e-mails on a daily basis from people who, given their druthers, would rob us silly as fast as technologically possible. Of late, I've been getting a frenzy of bogus missives thanking me for the five thousand dollars or so worth of software, gadgets, self-help books, and lingerie I supposedly purchased on a famous online shopping service over the last five minutes.

Of course, if this message was a mistake, I'm helpfully directed to an online form, where, upon disclosing my credit card data, someone will presumably clean my financial clock in nanoseconds.

What fun. Good to know that there are so many people out there who care. But better to know what the most common scams look like. Here is security vendor Panda's new list of the biggest Web scams of the decade.

The Nigerian scam. You knew this was going to top the list. Basically, you get a message from someone who identifies himself as an ex-government official in Nigeria. Could be some other country too, but Nigeria excelled early in this activity. The scammer says he has a truckload of money to get out of the country, but first needs a bank account to transfer it to (yours) and will then gladly give you a percentage of the cash for your assistance.

Amazingly, the victims of this grift are often so convinced (or perhaps blinded by greed) that they will then forward cash for "bank fees" and other bogus expenses in order to make the deal happen. Panda says these phony fees go as high as $1,000, and of course, no money is forthcoming from the scammer.

One ex-scammer says that nine or ten out of every 1,000 e-mails sent out get a response. "Then maybe 1 out of every 20 replies would lead to us getting money out of the victim in the end," he explained. Despite the efforts of the Federal Bureau of Investigation and a small army of scam baiters, this awful racket is still going strong.

Lotteries. Congratulations, you've won the lottery! We just need you to pay a small up front "fee" in order to get it. These often go as high as $1,000 as well. Needless to say, you never see the payoff.

Like the Nigerian scam, you can file the lottery scam under the larger category of "advance fee" frauds.

"The variety of advance fee schemes is limited only by the imagination of the con artists who offer them," the FBI notes. "They may involve the sale of products or services, the offering of investments, lottery winnings, 'found money', or many other 'opportunities'."

Bogus girlfriends. The con-artists who work this grift find their marks on dating chat boards and similar venues. They chat, IM, exchange photographs and videos... then comes the pitch. They really want to meet you, you sexy devil, but they need cash for the plane trip. Or even better, they're stuck in a hotel somewhere and have run out of funds. Plus their mom/daughter is sick and an evil ex-boyfriend is chasing them.

Oh kind, handsome sir—help, help, help! You get the idea.

Apparently it works. "Unsurprisingly, after she receives the money, she vanishes," Panda notes.

Make big bucks working at home. Our internationally unknown firm needs a financial agent in your area, the e-mail explains. This is an exciting opportunity for you to partner with us. All we need is your bank ID number and security information, and your help in transferring money in and out of your account.

But this piece of nastiness is worse than the Nigerian dodge, because what you'll actually be doing is siphoning other people's scammed cash in and out of the country—until the cops get wind of the situation.

In effect, these victims "become 'money mules'," Panda warns, "and when the police investigate the theft, they [the mules] will be seen as an accomplice."

The Facebook/Hotmail heist. Once these creeps get hold of your social network account, the sky's the limit as far as what they'll try to pull off. These days, the preferred shark attack is to change the account password so you can't get back in, then post a message to all your online friends claiming that you're on vacation somewhere in, say, London, and you were robbed. Help! Send money!

If you're on Facebook or Buzz and you see this kind of message, call your buddy ASAP to make sure they know what's going on. And make sure your kids (and you) know about complex passwords and the hazards of using public computers or unsecured WiFi systems to log in to social networks and other sensitive sites.

Hmmm, we made a mistake. This ploy has seen lots of action on sites like eBay and Craigslist, and it's making a comeback with the recent financial crisis. Somebody wants to buy something from you. They send you a check. But oops, gosh darn it, they sent you too much money. Would you please be a sweetheart and wire them back the difference?

Only one problem: "The [original] check will bounce and the victim will lose any money they transferred to the criminal," Panda explains.

Everybody always marvels that consumers continue to fall for these scams. How can anybody be this dumb? But keep something in mind: the number of people in cyberspace is constantly expanding. And the newbies don't know what you know. They're often people in those "underserved" areas who are just getting started. Or they're very young (or very old) and still finding their way around a new medium.