Amazon.com Inc and Microsoft Corp filed lawsuits against US and Canadian companies they claim used their names to commit fraud on the Internet.
One suit accuses Gold Disk Canada Inc. of online forgery known as "spoofing" by sending e-mails that appear to come from Amazon.com and Microsoft's Hotmail.com, the companies said in a statement.
Others are accused of using phony Amazon.com e-mail and Web sites to trick consumers into providing personal financial information, known as "phishing."
Microsoft has filed 70 similar suits since June to put financial pressure on companies that send unwanted e-mail, known as spam, and to warn others that spoofing and phishing are illegal, said Tim Cranton, a Microsoft senior attorney.
Spam costs US businesses as much as US$87 billion a year, according to the Pew Internet and American Life Project.
"We work really hard to establish a relationship of trust with our customers," said David Zapolsky, an Amazon.com lawyer and vice president. "When people use our name to get by spam filters, it's an abuse of our trust."
Phishing attacks rose in each of the first five months of this year, to 1,197 in May from 176 in January, according to the NASD, formerly the National Association of Securities Dealers.
Citigroup Inc's Smith Barney brokerage unit said its customers have been targeted by a phishing scheme and yesterday posted an alert and a sample of a phony e-mail on its Web site.
The US Federal Trade Commission and the US Justice Department in April filed the first criminal charges against spammers under a federal law banning unsolicited e-mails that took effect Jan. 1.
Microsoft has been awarded US$70 million in damages in its cases so far, of which it has collected "several hundred thousand dollars," Cranton said.