Microsoft on Thursday filed a so-called John Doe suit in the federal court for the northern district of California in San Jose. The suit doesn't name defendants, but allows the plaintiff the power to issue subpoenas as part of the investigative phase of the trial.
The defendants are accused of using a "dictionary attack" to discover active Hotmail accounts. A dictionary attack is one in which a computer program goes through every entry in a dictionary in an attempt to guess passwords. In this case, the program guessed millions of random e-mail addresses to see which ones were active, Microsoft alleged.
Microsoft filed the suit the same week it called on legislators to pass laws forbidding the practice of spam-address harvesting.
"We are intensifying our efforts to cooperate with other ISPs in fighting spam, and working with (the) government to enforce current laws against it," Microsoft wrote in an essay dated Wednesday. "But new, strong laws are needed. At a minimum, senders should not be allowed to misrepresent their identity, falsify the subject of a message, or use automated means to gather e-mail addresses without the owners' consent."
In the absence of such a law, Microsoft relied on existing federal statutes including the Computer Fraud and Abuse Act. The company also made trade secrets and trespassing claims.
Internet service providers and individuals alike have increasingly turned to the law to fight unsolicited commercial e-mail.
AOL Time Warner's America Online unit, for example, in April won an injunction and secured a "significant" monetary settlement against a spammer. EarthLink in July secured a judgment worth more than US$24 million in a comparable case.
Microsoft said that legal action was only one part of its antispam campaign.
"No one thing is going to be the answer," said a Microsoft representative. "Not filters alone, or education, or the law. Microsoft thinks a multipronged approach is going to be the most effective."
