The actions announced by America Online, EarthLink, Microsoft and Yahoo were said to be first major industry lawsuits under the new federal anti-spam law, the Controlling the Assault of Non-Solicited Pornography and Marketing (CAN-SPAM) Act, that came into effect from 1 January.
Each of the four companies filed separate legal complaints in federal courts in California, Georgia, Virginia and Washington, against six operations said to be responsible for hundreds of millions of bulk spam e-mails to customers of the four networks.
"We are trying to hit the biggest, the baddest, the most notorious spammers," Randal Boe, general counsel for America Online said.
"The next step will be to put them out of business," he said.
Some surveys say spam accounts for half or more of e-mail traffic.
"We are trying to hit the biggest, the baddest, the most notorious spammers"
General counsel, America Online
The new US law provides tougher penalties for spam and allows legal action against all those involved in the process, including the sellers of products and services and subcontractors for e-mail campaigns.
The four companies formed an anti-spam alliance in April 2003 in a bid to pool their resources to fight what some say is a plague on the Internet.
"Together, we are using a tough new federal law, combined with existing state laws, to let criminal spammers know that the nation's leading Internet providers are united by a common goal," EarthLink general counsel Les Seagraves said.
The lawsuit in some cases named "John Doe" or unknown defendants, but the companies said the identities were likely to be obtained through the courts.