Once a sucker, always a sucker.

Unfortunately, that seems to be the current thinking of today’s con artists who, according to a new survey, are specifically targeting consumers who’ve already fallen victim to a scam. Below, I’ll explain how this fraud works, so neither you nor your parents get fleeced.

Known as “refund and recovery scams,” these sucker list schemes are not only new to the recently released annual Top Scams list from the National Consumers League's fraud center, Fraud.org. They’re also the fastest growing non-Internet fraud.

(MORE: Imposter Scams Are Soaring)

How the 'Sucker List' Scam Works

Here’s the gambit: Scammers buy, sell and trade lists of consumers who’ve fallen for a phone, mail or email scam. The fraudsters then use these lists to call or mail those victims, claiming they can help recover their lost money for a fee. In reality, says Fraud.org, the sales pitch is just another scam designed to get even more money from these folks.

“The pitch varies from scammer to scammer, but it’s usually something like, ‘I know you’ve lost money and I’m going to help you get it back,’” says John Breyault, NCL’s Vice President of Public Policy, Telecommunications and Fraud and manager of the group’s Fraud.org campaign.

Given the rapid increase in complaints this year, Breyault adds, it’s clear that scammers have become “more networked and organized buying, selling and trading these lists.” Translation: “If you’ve been defrauded once, chances are you’ll be getting phone calls from more scammers,” says Breyault.

So how do you avoid getting on the sucker list? Breyault has a three-word answer: “Trust no one. If you get an unsolicited call asking for sensitive personal information, never give it out.”

(MORE: Lowdown on Scams, Schemes and Swindles)

And if you have been a fraud victim, consider changing your telephone number. You’ll then avoid getting contacted by con artists who found you on a sucker’s list. “Short of disconnecting your phone, it may be the only way to stop some of these calls,” Breyault says.

Other Disturbing Findings

Fraud.org’s new scams list, based on more than 8,000 complaints filed in 2013, has some other disturbing findings as well, including a sharp increase in telemarketing scams.

Until last year, the largest percentage of scam complaints cited the Internet as the original point of contact. But in 2013, according to the report, “the most frequent way scammers approached consumers was over the telephone,” accounting for more than one-third of complaints.

Breyault suspects this is partly due to the prevalence of the lottery/sweepstakes scam. That’s the one where telemarketers call, saying you’ve won the lottery or a sweepstakes and that the money can yours if you pay a fee (often hundreds of dollars or more). “There are no winnings,” Breyault says.

(MORE: How to Avoid the Latest Consumer Scams)

Also contributing to the rise of telemarketing scams: con artists’ growing ability to use computers to call thousands of consumers in a short period of time and at a very small expense. The telemarketers often trick Caller IDs into showing the calls are made by legitimate concerns.

You’ve probably heard of this tactic, called “spoofing.” As a result, Breyault says, “You can’t trust your Caller ID anymore.”

Better Business Bureaus' Scams List

Indeed. The Better Business Bureau’s just-released list of Top 10 scams includes the “arrest warrant scam,” which uses spoofing. Here, con artists’ calls look like they’re coming from sheriffs of other law enforcement agencies. The fraudsters say there’s a warrant for your arrest, but you can pay a fine to avoid the charges. Of course, these “police” don’t take credit cards; “only a wire transfer or prepaid debit card will do,” the BBB says.

Breyault worries that spoofing may become a more serious problem in the months ahead as fraudsters exploit data break-ins such as the recent breach at Target. He says he wouldn’t be surprised to hear about telemarketers pretending to be from Target calling consumers to confirm their financial data by giving out their Social Security numbers or bank or credit-card accounts.

Friendship and Romance Scams

Since Valentine’s Day just passed, you may have also heard about friendship and romance scams. In those, con artists initiate relationships through online dating sites and then become friendly with potential victims through email correspondence. Eventually, the fraudsters ask for money, claiming an emergency, such as a stolen wallet or sick relative. Or they may ask for airfare to meet the victim. More often than not, once a request is met, others follow.

According to the NCL report, these scams account for a relatively small number of complaints (less than 1.5 percent in 2012 and 2013). But, Breyault notes, they are the most expensive, with the average per-victim loss at $13,000 in 2013. “Love is the most powerful emotion we have,” Breyault says, “so it’s easy to see how a scammer can use that to gain somebody’s confidence and how it can result in a lot of losses.”

One Piece of Good News

Amid all the bad news, the NCL report has one small sliver of good news: Consumers falling for scams are increasingly paying by credit card. Unlike wire transfers, credit card payments can be challenged — and refunded — so consumers may be able to get their money back. “With a wire transfer, once the money’s gone, it’s gone for good,” Breyault says.

3 Ways to Stay Safe

Since con artists are growing more devious, here are three ways you and your parents can stay safe:

1. Always be wary. If a telemarketer calls, never give out personal information unless you’re sure the query is legitimate. Look up the phone number for the company allegedly making the request (don’t call back the number on Caller ID). Then contact that firm to make sure the request is legitimate.

2. Use a credit card if you’ll be paying someone you don’t know. This way, you’ll have an opportunity to dispute the charge and have the debt forgiven if it’s bogus.

3. Report any suspicious activity. “These guys will never stop unless people report a crime,” says Breyault. Filing a complaint at Fraud.org is a good place to start, he adds, since its information is shared with more than 90 consumer-protection and law enforcement agencies.