Some of the largest internet service providers (ISPs) in the United States have today joined forces to sue hundreds of people they allege have flooding the internet with unsolicited e-mails, or spam.

Microsoft, AOL, Earthlink and Yahoo! have filed six lawsuits naming hundreds of individuals in the first legal action by the industry under new laws to tackle the problem.

The lawsuits, submitted to federal courts in California, Georgia, Virginia and Washington State, were announced at a news conference and are the result of the new "Can Spam" legislation that came into effect on January 1.

The companies said the defendants include some of the nation's most notorious large-scale spammers.

The ISPs – collectively with tens of millions of subscribers – said they shared information, resources and investigative information to identify some of the defendants.

Randall Boe, the executive vice president and leading lawyer at AOL, said: "Congress gave us the necessary tools to pursue spammers with stiff penalties, and we in the industry didn't waste a moment moving with speed and resolve to take advantage of the new law."

Dozens of those named in the lawsuits were only identified as "John Doe" however. They were accused of e-mailing unwanted advertising for prescription drugs, herbal potions and weight loss plans.

Among the named defendants were Davis Wolfgang Hawke of Massachusetts, whom AOL lawyers said is also known as Dave Bridger, and Braden Bournival of New Hampshire.

They and others were accused of sending millions of e-mails offering weight loss supplements, handheld devices called "personal lie detectors" and other products.

The "Can Spam" legislation, which is an acronym for "controlling the assault of non-solicited pornography and marketing", requires unsolicited e-mails to include a mechanism so recipients could indicate they did not want future mass mailings.

The law prohibits senders of unsolicited commercial e-mail from disguising their identity by using a false return address or misleading subject line; it prohibits senders from harvesting addresses from websites; and prohibits the use of third-party computers to conceal the spam's origin.