Keep a sharp eye out for these scams

The holidays are approaching. Get ready to be scammed.

One of the main areas to be wary: shopping online, where Forrester Research projects consumers will spend $45 billion this holiday season, up 8 per cent from last year. One of the biggest problems isn't even illegal.

How to protect yourself from card scams
Five tips for protecting your online bank accounts
10 ways to spot a scam
The world's most exclusive credit cards
10 ways to wreck your credit score
Managing your online identity

Those seemingly innocuous pop-up advertisements promising cash back rewards if a shopper clicks "yes" after completing an online purchase with a credit or debit card pose particular hazards, say experts.

What the shopper has unwittingly done is agreed to a subscription service that dings him for $20 or so a month, often for months, until detected. If you think no one actually clicks on these things, think again.

The three main companies doing it--Affinion, Vertrue ( VTRU - news - people ) and Webloyalty--have collected and shared $1.4 billion of revenues with major e-commerce partners over the years, including popular airlines and travel aggregators, according to a report by the Senate Commerce Committee, which held hearings on the issue this week.

"Millions of Americans are getting hit with these mystery charges every month--we have to do all we can to protect the hard-working families relying on us to look out for their wallets and well-being," says Committee Chairman John Rockefeller, D-W.Va.

The Senate report says 30 million consumers are enrolled in these membership clubs, which purport to offer promotions on products and services, though almost no one receives the promised cash-back awards.

More than 450 e-commerce Web sites and retailers have partnered with the companies, splitting fees 50-50 in return for handing over their customers' payment information. That's how the three firms get access to peoples' credit card--or worse, debit card--accounts to charge them.

Canceling out of the programs can be tedious and time consuming, as several consumers have testified. The practice is technically legal, but lawmakers are questioning whether the marketers' tactics are too aggressive or deceptive.

Consumer advocates are hoping shoppers become more wary of pop-ups and other advertising they see online this season. But they are also reminding shoppers of basic credit card and debit card safety tactics.

Don't use a debit card, for example, where you could use a credit card, says Public Interest Research Group Director Ed Mierzwinski. Debit cards, which look just like credit cards but are directly linked to a checking account rather than a revolving line of bank credit, don't have the same safety protections.

Consumers purchasing items either online or in a store using a debit card could be subject to substantially more losses if the card information gets into the wrong hands because debit cards don't have the strict liability caps of credit cards.

In general, a credit card customer would only be liable for $50 in fraudulent charges. That limit only applies to debit card holders if they report the suspicious charges within two days.

After 60 days, the debit card holder could be liable for $500 in losses. That comes directly out of their own checking account. At least with a credit card, the disputed amount is coming out of a credit line and not a cash line.

Another reason to keep the debit cards at home and carry a limited amount of cash and only one or two credit cards: skimmers stealing data. A skimmer is a device that looks like a legitimate card reader (like the ones they have in the check out aisle) but is merely recording the data on the card's magnetic stripe to be used fraudulently later.

Thieves have been using skimmers in increasingly sophisticated ways, including a case in Atlanta where a ring of bandits managed to attach skimmers and cameras to legitimate automated teller machines and made them look like the real thing. Two pleaded guilty earlier this month.

"Illegal skimming for personal gain is a 'high-tech' crime and we have adapted our technology and assets to further the investigations of this specific type of electronic crime," said Jeffrey Gilbert, a special agent of the Secret Service in Atlanta, in a statement announcing the guilty pleas.

So as the holidays approach, keep a sharp eye out for scams that could trip you up in the new year.