Rather than being disturbed by the availability of data, Yepremian said it has been a useful tool when deciding whether to grant applicants a loan.
"If I want to lend money to someone, I want to make sure that everything and anything they've told me is the truth," Yepremian said. Even a few years ago, verifying an applicant's claims might have required a call to a title company or a crosstown drive to inspect a property. Now the Web saves him the trouble. "It makes life much easier," he said.
Perhaps the least understood by consumers is the practice of behavioral tracking, where marketing companies log activities such as the Web pages users visit, the ads they click and the terms they search for.
Most companies say information about user activities is stored securely and anonymously.
Even so, Paul Stephens of the Privacy Rights Clearinghouse said, "an individual's patterns on the Internet can reveal a tremendous amount of information about them, and it can be a gold mine for companies that want to market to you."
Privacy advocates say many consumers are hardly aware that any of their online activities are being stored, much less analyzed for marketing purposes.
"The standard online right now is that your information is taken and used unless you opt out," Stephens said. But in order to do so, consumers must first realize there's something to opt out of. That will require greater transparency on the part of those collecting information, Stephens said.
Behavioral tracking has an Orwellian ring to it, but the ability to efficiently guess consumers' desires is fundamental to the fast-moving world of online marketing.
"Many of our favorite sites on the Web are supported by advertising," said Alissa Cooper of the Center for Democracy and Technology. "It's an incredibly important piece of the fabric of the Web."
That's why banning behavioral tracking is not the solution, Cooper said. "The real key is for consumers to know what is going on and to be able to make an informed choice about whether they want their data to be part of the process."
Limiting your personal exposure
With little federal regulation of the use of information that companies collect online, consumers are often left to their own devices to protect themselves.
Googling your own name has often been referred to as "vanity searching" -- but now it's better thought of as vigilance.
Use search engines to keep track of what's out there about you and to spot unwanted leaks early. "People search" sites such as Snitch.name, Spock and PeekYou can also be useful when trying to clean up your digital breadcrumbs.
If you find information about you on a website you believe has no right to it, write to the site owner and request that it be removed. Getting a response may be difficult, however, as many of the sites that compile and store such details are automated. If the data is particularly sensitive, ask a lawyer for advice.
Social networks such as Facebook give users relatively high levels of control over who sees their data, but don't assume that your profile is private by default: Often you'll need to tighten the settings yourself to deny access to people you don't know.
Many government records are public by law, and preventing them from appearing online can be difficult, said Dixon of the World Privacy Forum. But consult a lawyer; judges are able to seal some documents and records, generally before they go online.
It's also possible to avoid certain types of behavioral tracking. One of the easiest ways is to restrict your Web browser's use of "cookies" -- the tiny data mechanism that helps sites keep track of your browser.
By regularly clearing your cookies, you can cut down on the number of clues you're offering to marketers regarding your browsing habits. Look for a privacy setting in your browser's "Options" area that allows you to limit which types of cookies your browser accepts and how quickly they expire.
The growth of the Internet may actually spur the evolution of digital privacy, said Cooper of the Center for Democracy and Technology.
"Consumers are becoming producers and putting their own content on the Web," she said. "With that comes the urge to be able to control who sees what."
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How to keep a low profile
Find out what's already out there by searching for your own name with services such as Google, 123people.com, PeekYou.com and Snitch.name.
If you find something you don't like, write to the site owner and ask that it be removed; contact information is available on many sites. In the case of serious breaches, ask a lawyer for advice.
When starting a profile on a social network such as Twitter, Facebook, YouTube or Yelp, consider using a nickname or a variation of your name. That way information you post will not be linked to your real name.
On social networks, accept "friend" requests only from people you know and trust. Never accept requests from strangers.
When involved in a lawsuit or other public proceeding that deals with sensitive information, look into having it sealed by a judge.
-- David Sarno