I just got an email from our friend Beverly, saying that she is in Pakistan and she's just been pickpocketed. She has no money and no passport, and she needs $2,500 to get home.

If anyone we know would get pickpocketed in Pakistan, it's Beverly. I know people who are scared to go downtown, but Beverly is fearless -- she's been all over the world, speaks several different languages and loves to travel. But even if I send her the money, there's no way she's going to get home without a passport -- and she could hardly pay me back by working in some sweatshop making hoodies for 50 cents an hour.

But since Beverly is sitting in our living room at the moment, right next to Sue, it occurred to me that I could just ask her.

"Maybe I'm just naturally suspicious, but why did you say you're in Pakistan if you're right here?"

"What are you talking about?" she said. I showed her the email.

"I've been hacked, Sherlock. They must have sent this to everyone on my contact list. That's, like, 500 people. I hope they have more sense than you. It's Scam 101. I'm hoping you're the only one who's dumb enough to fall for it. Why would I ask you for money and not, oh, I don't know, my mother or my brother? Didn't that seem a little odd to you? Plus the fact that I'm right here in your house and obviously not in Pakistan. And I've been here many times. I've seen the way you live -- there's no way you would have $2,500 lying around."

"I didn't come here to be insulted," I told her.

"Really?" she said. "Where do you go?"

Sometimes I forget why we're friends with Beverly.

But she's right about scams. Yesterday I got an email about an old table we're trying to sell on Craigslist. It said that the buyer was very busy and had no time to come get it, but he would send me a cashier's check for the table and that he was going to add $50 to the price for the inconvenience. As soon as the money cleared my account, he would send someone to pick it up.

Just as it seemed odd that Beverly had no money but was still able to email us from Pakistan, it also seemed odd that the guy who wants our table tells us how busy he is, but he has plenty of time to run to the bank and get a cashier's check.

We live in a scammer's paradise now, thanks to the internet. We're all familiar with the famous "Nigerian prince" setup, where someone from a third-world country needs your help to move millions of dollars from his corrupt country to our not-quite-as-corrupt county. For doing that, he will give you some of his millions.

But the internet also let me do an instant search for "Craigslist certified check scam" and find out what's really going on. The con is simple: The guy really will send you a certified check (completely fake, of course) and your bank will deposit the money in your account. The bogus check will clear. About two weeks later, the bank will call and tell you the check is bogus and take the money out of your account. By then, whatever you sold is long gone, already pawned or resold by your friend, Connie P. Artist.

Who knew the bank couldn't tell the difference between a real certified check and a fake one the moment they received it? Even the smartest people in the world could fall for this, so how is a normal person supposed to know who to trust and who not to?

Well, think of it this way: If someone offered you a certified check at a garage sale, what would you say? If someone can send you an email asking for $2,500, why can't they call you on the phone?

If something sounds off-kilter, it probably is.