Consumer jitters over security cost online retailers nearly $2 billion in lost sales so far this year, according to survey results released Monday by research firm Gartner.

The Web-based poll of 5,000 U.S. adults pegged the losses at just over $1.9 billion, said Gartner analyst Avivah Litan. About $913 million of that total was lost because of security worries by current online shoppers, who scaled back their spending; $1 billion in lost revenue was "credited" to shoppers who completely refused to shop online because of the same security concerns.

Just over 46% of the 155 million U.S. adults who go online, said Litan, admitted that misgivings about information theft, data breaches, or Web-based attacks have affected their purchasing, online transaction, or e-mail behavior. Of all online consumer behaviors, e-commerce -- which includes online banking, online payments, and online shopping -- suffered the most in 2006.

Not that it makes a lot of sense, said Litan. "People are a little irrational about e-commerce. If you look at the data breaches, for example, four out of five card data breaches are at point-of-sale, not online," she said. "But people take out all the security problems on online. It's not irrational to worry about security, but it is lopsided toward online."

By Gartner's estimates, security concerns have kept about 33 million Americans from banking online; 9 million were consumers who once banked online but stopped the practice in 2006 because of security anxiety.

Most striking, however, was the rapid change in attitude toward e-mail. Consumers now have a serious distrust of all e-mail thanks to phishing attacks and malicious code delivered via the technology. About 7 out of every 10 who acknowledged a behavior change because of security said that their trust in messages from companies and people they don't know has been affected. Of that number, 85% simply delete suspect mail without reading or opening.

"The educational efforts of all the ISPs, all the banks, and sites like PayPal about not responding to messages from unknown senders has worked," said Litan. Perhaps too well. In fact, the wariness about e-mail is a bigger concern for banks and other companies than fraud itself.

"They're more concerned about this fall in consumer confidence than they are about fraud," said Litan.

The reason is simple economics. "It costs them $7 to answer the phone" when a consumer calls, Litan said. "A 20- to 30-minute call is at least $30. Compare that to a couple of pennies for self-serve help over the Internet or by e-mail."

Banks in particular will face tough going if consumers continue to steer clear of online banking. E-banking, said Litan, costs institutions less than a hundredth the amount spent to handle an in-branch transaction. Compare such huge increases in costs with the half-to-1% fraud rate, and it's easy to see why banks worry about the drop in confidence.

"Short term there are some tactical things that banks are doing, like personalizing e-mail. They're also moving away from sending statements by e-mail and instead are just sending messages that tell customers their statement is ready and available on the site," said Litan. But in the end the only thing that will turn around consumer confidence will be a safer Internet. Among her recommendations: stronger user authentication that moves beyond the usual user name and password.

Gartner's results conflict with a survey published earlier in November that said consumer morale was on the upswing. That poll, done for online payment provider CheckFree and seconded by James Van Dyke, an analyst with Javelin Strategy & Research, claimed that the number of people who don't trust the Internet with financial information dropped to 8% this year from 20% in 2004.

"The panic is over," Van Dyke said in a Nov. 2 interview.

Litan disagrees. "Phone-based surveys just don't work when you're asking about online shopping and banking," countered Litan, who said Gartner's Web-based polling results were backed by similar studies done by the Federal Trade Commission. "You start asking people about security and online banking, and they just hang up."

Litan authored a similar survey in 2005, but "it's not apples to apples," so direct comparisons are difficult. However, she concluded that although the number of Americans whose behavior has been affected by security concerns remained about the same this year as in 2005, "there's more of a financial impact now. More people are spending much less.

"And last year, people were just worried. Now they're changing their behavior."