Computer software giant Microsoft is taking legal steps to crack down on Internet scammers who trick Web users into revealing personal and financial information.

It is called "phishing," and almost anyone who uses the Internet is a potential target. Tricksters compose messages that look virtually identical to the Web sites of major financial institutions, like banks and credit card companies.

These fraudulent messages are sent out en masse with a request for customers to "verify" information, including names, addresses, account numbers and social security numbers. Information received from unsuspecting consumers can be used by criminals to access bank accounts, make unauthorized credit card purchases, or even commit identity theft.

Thursday, Microsoft announced it is filing 117 lawsuits against "phishers" in federal court in Seattle, Washington. Aaron Kornblum is an attorney for the corporation's Internet safety enforcement division.

"The phishers targeted in this series of lawsuits created fake, deceptive Web sites between October 2004 and March 2005," said Aaron Kornblum. "And by filing these lawsuits, it invokes the power of the court, and permits Microsoft to issue subpoenas to third parties, who, we believe, have information regarding phishers."

The defendants in the lawsuits are listed as unknown, or "John Doe", for now. That is because tracing a phishing message through cyberspace to the actual person who created it is no easy task. But by initiating legal action, Microsoft hopes to gain access to records from Internet service providers and other parties who can aid them in the search.

Microsoft says it hopes to make examples of phishers to deter others from engaging in the practice.

U.S. authorities are joining the battle. Appearing at the Microsoft announcement was the acting director of the Federal Trade Commission's Bureau of Consumer Protection, Lydia Parnes, who said Internet users must be made aware of fraudulent schemes.

"Identifying individual phishers is extremely difficult," said Lydia Parnes. "But if consumers know not to e-mail their personal financial information in response to a pop-up solicitation or an e-mail inquiry, they can protect themselves."

The FTC has created a list of rules for safer Web use. Rule Number One:

"If you get an e-mail or a pop-up message that asks you for personal or financial information, do not reply," she said. "Do not click on the link. Legitimate companies do not ask for this kind of information by e-mail. Just delete the message."

Other rules include: never e-mailing personal or financial information to anyone, carefully examining all credit card and bank statements as soon as they are received, and installing anti-virus software on all computers.