It's no secret that criminals are stealing credit card and bank account data and selling it underground. But most people would find it shocking to learn just how little their sensitive personal information costs.

Symantec on Thursday is launching its Norton Online Risk Calculator, a tool that people can use to see how much their online information is worth on the black market. The tool also offers a risk rating based on demographics, online activity, and estimated value of online information.

I tried the tool when I was initially briefed on it a few months ago and was surveyed about my gender and age range; online assets (including credit card and bank account data, brokerage accounts, e-mail accounts, and social network accounts) and an estimated value of all that information; whether I use security software; how cautious I am when online; and how much I think my information is worth.

I use security software (and do my financial transactions mostly on a Mac at home), am fairly cautious while Web surfing, and didn't put a high dollar figure on the value of my digital information. My security risk turned out to be 37 percent, or medium, and the black market worth of my online assets was calculated to be $11.29. Those figures didn't change when I modified the gender, age, and estimated value of the data.

A recent Microsoft Research report concludes that stolen data offered for sale in underground IRC channels is difficult to monetize because of all the--get this--con artists there.

Regardless of whether the underground revenue figures are overblown, the data is being harvested, sometimes in huge batches, during data breaches at large payment processors, and there is a market for it.

It's discomfiting to think a criminal could pay as little as $11 to get access to my sensitive personal data for identity fraud purposes, while I could end up spending lots of energy and time--years even--reporting the crime, trying to fix my credit rating, and getting my life back to normal.

Symantec isn't trying to scare consumers with the Norton Online Risk Calculator, but to raise awareness of the risks, said Marian Merritt, Internet safety advocate at Symantec.

"We still find consumers who think using just antivirus is sufficient," she said.

Merritt recommends that people use security suites that offer antivirus, firewall, and intrusion detection and prevention software, as well as keep their operating system and browsers updated.

Support for extensions to customize Chrome, the top-requested feature for Google's browser, has begun arriving for adventurous users.

Previously, extensions worked only for those who enabled the feature with a command line switch. Now the feature is enabled by default in the developer preview version of Chrome on Windows, Aaron Boodman, the Google engineer who oversees the extensions work, said in a blog post Wednesday.

"We're ready for a few more people to start using extensions--the kind of adventurous people who populate the dev channel," said Boodman, who earlier in his career developed the Greasemonkey tool that permitted extensive customization of Firefox.

Work is already under way for some popular extensions, including Yahoo's Delicious for social bookmarking and Xmarks for bookmark synchronization.

Extensions are enabled by default only for Chrome's Windows users right now. "We've also enlisted some help to get extensions up to speed on Mac and Linux," Boodman said.

The extension-programming interfaces have been changing, and more changes are coming to the user interface. Those who want to start developing extensions should look at the new Chrome extension documentation.

Chrome extensions are written with the same programming technologies as are used for Web pages themselves--HTML, CSS, and the like. Mozilla has a related extension effort called Jetpack under way for Firefox.