Three Web sites that provide spam blocking lists have shut down as a result of crippling Internet attacks in what experts on Thursday said is an escalation in the war between spammers and opponents of unsolicited e-mails.
The technological war comes as Congress considers a federal anti-spam law and California adopts what is widely considered to be the toughest law in the country. The California law, signed on Tuesday, allows people to sue spammers for $1,000 per unsolicited e-mail and up to $1 million for a spam campaign.
"This definitely marks an escalation in the spam wars," Andrew Barrett, executive director of The Spamcon Foundation, a spam watchdog group, said of the recent Internet attacks on lists used to block spam.
Two of those spam block lists have shut down after being attacked by denial-of-service attacks, in which compromised computers are used to send so much traffic to a Web site that it is temporarily taken down. The operator of another list shut down fearing a pending attack.
"There seems to be a methodical well-planned attempt to use pre-assembled networks of zombie machines to create sustained denial of service attacks on servers where these block lists run," said Barrett.