Every time you're online, marketers, game developers and search engines are trying to suck up as much information about you as they can. And they hope to use that information to make lots of money off you someday.
But with data breaches and self-inflicted privacy gaffes -- former Rep. Anthony Weiner, what were you thinking? -- becoming a more common occurrence, more people are fighting back against the invasiveness of some technologies, and are trying to wrangle their digital identities back under their control.
They're finding that there are worthwhile steps to take, but no single solution to control the staggering amount of personal information out there on the Internet.
San Francisco Bay Area resident Nan Lee, for example, recently Googled her name along with her city of residence. On one site, U.S. Identify, she found what she felt was too much information, including her addresses going back nearly 20 years.
"I was really creeped out that all this info came up in an instant through such a simple search," she said.
And a free search at data-aggregation sites like Spokeo or Intelius, for example, may show your address and phone number, a photo of your home's exterior (courtesy of Google Street View), whether other people live with you and their names. You might even find some of your habits or preferences listed, such as "researches investments" or "cares about healthy living."
"Sitting down and taking an inventory of what your digital tattoo really looks like, it's a lesson for a lot of people," said Janice Chaffin, president of the consumer business unit at data security company Symantec, based in Mountain View, Calif. "There is so much out there."
Even Chaffin, whose professional life is devoted to keeping computer users' data safe, got a first-hand lesson in the associated issue of online privacy recently. She and one of her daughters sat down to look at what information was easily available online about the teenager.
They discovered that something the girl had written about on social networking site Formspring was showing up in her profile on an aggregator's site in an unflattering way. Chaffin's daughter canceled the Formspring account. But doing so doesn't guarantee the information will disappear, and Chaffin said removing unwanted data can be a time-consuming process.
Lee, who's trying to remove her information from the U.S. Identify site, said the company told her it could block her records from searches if she provided them a long list of personal information, including all her addresses since 1991. Lee said she's not happy about all the work involved.
"Why isn't there a faster, equally secure way to verify a person and his or her removal request?" she said.
A spokesman for Texas-based U.S. Identify said the company needed detailed information to ensure it would be deleting information about the correct person, and doing so thoroughly.
Individuals can opt to be removed from Spokeo, but unless they take steps to hide the public information upon which their profile is based, the same data may show up elsewhere. And because that information is scattered across property records, phone books and more, removing it can be difficult.
While deleting information from public sources is tough, blocking marketers from tracking one's online browsing should be easier, said Jim Brock, founder of PrivacyChoice.org, based in Santa Cruz, Calif. Consumers can use tools available at PrivacyChoice.org both to determine what some online marketers know about them, and to prohibit their browsing from being tracked.
And "Do not track" legislation pending in Congress and in the California Legislature would allow consumers to more easily opt out of having their browsing monitored.
"Folks don't probably understand that as they use the Web and post information, that companies are getting very good at associating that back to an email address," Brock said. And when someone includes an email address on a job or college application, information about that person's online activities "is now on tap for anybody who can afford to look it up."
As he spoke, Brock typed his name into a site run by online marketing data company BlueKai, which is based in Cupertino, Calif.
"They know where I live, they know I have children in the household, they know I run a small company, they know my age, they know my gender, they know we prefer natural foods," and more, he said. But, "They think I own a Buick, and that's not right."
Given the growing privacy concerns, plenty of companies have sprung up to help people manage their online "reputations." Redwood City, Calif.-based Reputation.com is one that can help squelch negative information about a person or company; Google also recently announced a service called "Me on the Web," designed to help Internet users keep track of what's being said about them online.
But maintaining an appropriate level of personal privacy is a complex and individual issue. Not everyone agrees about whether being tracked by marketing companies or sharing photos online is good or bad. The information that marketers glean can be used for a consumer's benefit -- ads appearing on your screen as you browse will be more relevant to you if you're being tracked, for example.
What unnerves some people, Brock said, is unknown future uses of the vast stores of information about us.
Advances in facial recognition software mean that online photos of you -- even those uploaded by your friends -- could someday be linked to your email address and up for sale, for example.
"Private companies are developing giant indexes of the world's faces," said Brock, who cites the Israeli company Face.com as an example. In his opinion, it should be clear to people how they can opt out. "I just want to make sure the technology to enable consumers' choice keeps pace with the technology to track and identify."