(MONEY Magazine) – With more and more confidential information whipping around the Web, it's not surprising that privacy is becoming an increasingly public issue. In March, after an outcry from privacy advocates, the giant Internet advertising firm DoubleClick backed off a plan to create detailed consumer profiles by combining a database of names, addresses and other personal information with the anonymous Web click-pattern data it collects on consumers. Also in March, the Federal Trade Commission ordered Trans Union, one of the nation's three big credit reporting agencies, to stop selling the financial information that it has amassed on some 160 million Americans to certain marketers.

Congress has begun to take action as well. Last year's banking-reform bill includes a provision requiring banks and other financial institutions to allow consumers to opt out of having personal information shared with third parties. But the law won't take effect until November, and state-level measures--like a California "opt in" proposal to require financial institutions to get consumers' explicit consent before selling their information--are only now in the works.

In the meantime, there are two relatively effective ways to keep your information out of circulation--and to limit the number of sales pitches you receive by mail, phone and e-mail. The first is to request that you be left off marketing lists whenever you use a credit card, both online and off. And when dealing with a new merchant, check out its privacy policy. Even some sites that promise privacy leave themselves the option to one day sell your profile. Amazon, for example, says it "does not sell, trade or rent your personal information" but "may choose to do so in the future with trustworthy third parties." (You can, however, opt out by writing to Amazon at never@amazon.com.) Even charities and nonprofits generate revenue by selling the names and addresses of donors.

Second, have yourself removed from existing lists by calling or writing to the companies that sell them. And keep in mind that you may have to contact them annually or semiannually in order to remain off their lists. As Jodi Beebe of the Privacy Rights Clearinghouse says, "If your information is already out there and you decide to opt out, you still have to clean out the mess." The website of the Center for Democracy and Technology (opt-out.cdt.org) provides links for opting-out online. And here's a list of the largest vendors of consumer marketing data, along with contact information.

DoubleClick: www.doubleclick.com: 8080/privacy_policy/privacy.htm

Direct Marketing Association: Mail Preference Service, P.O. Box 9008, Farmingdale, N.Y. 11735; Telephone Preference Service: P.O. Box 9014, Farmingdale, N.Y. 11735; E-mail Preference Service: www.e-mps.org

Credit bureaus: 888-567-8688 (A single call will remove your name mailing lists sold by major credit reporting agencies. Trans Union, Experian and Equifax.)

Donnelley Marketing: 888-633-4402

Polk Co.: 800-873-7655

Acxiom Corp.: Attn: Opt-outs, P.O. Box 2000, Conway, Ark. 72033

Abacus Direct: 800-518-4453

--ERICA GARCIA