Microsoft Corp. unsheathed the big stick this week in its war against spam, filing 15 lawsuits in the U.K. and the U.S. against alleged distributors.

Microsoft claims that those named in the suits have flooded MSN electronic inboxes and Microsoft's systems with more than 2 billion deceptive spam messages.

Domestically, Microsoft invoked a Washington state anti-spam law that enables ISPs to take action against spammers and protect consumers. In London, the company is filing suit under the U.K Misuse of Computers Act of 1990.

"Spam knows no borders. It is an issue that requires global coordination, so that industry and government have the maximum ability to protect consumers," said Brad Smith, Microsoft's senior vice president and general counsel, in a press release.

Microsoft is charging alleged spammers named in the case of using deceptive subject lines to disguise email messages that contain pornographic images and dating service solicitations. Others sent messages with false virus warnings, urging recipients to download an "update" that instead tracks how they use the Internet.

Microsoft, in one case filed in Washington state, is alleging that firms Email Gold Inc. and NetGold, and individuals Linda Jean Lightfoot and Eddie Davis sent spam messages advertising a CD containing "the tools necessary to become a high-volume spammer."

In addition to taking legal aim at alleged spammers, Microsoft is also adding anti-spam technology in its MSN 8 platform and a future release of its Exchange and Outlook platforms.

Microsoft is also a lead member of a group that aims to create a number of anti-spam standards and best practices. Other members include Earthlink Inc., America Online Inc. and Yahoo! Inc.

Earthlink has also taken legal action against spammers. In May, it won a $16.4 million judgment against Howard Carmack, also known as "The Buffalo Spammer." Earthlink alleged that Carmack sent out more than 825 million spam messages since March 2002.