Spam increased by 161 percent from last September through June and now represents 94 percent of e-mail, according to Postini. But our survey respondents reported a lower proportion of spam reaching their In box than in the past. We believe the reason for this seeming contradiction is that spam-blocking has improved, both in quantity and quality: In our survey, 65 percent of respondents used their own spam filter, up from 59 percent last year. And large Internet service providers such as AOL and MSN have tightened their spam filtering in recent years.

While 30 percent of respondents who had received spam in the past month said they received pornographic or other objectionable material, that's 10 percentage points less than last year. In households with children online, 5 percent said a child saw pornography.

Of respondents who had received spam in the past month, just 28 percent fell for the trap of trying to remove themselves from the list by clicking on a link in the message, and just 17 percent tried to opt out by replying to it. Three years ago, both rates were about 40 percent.

Still, the fight against spam is far from over. Nearly half of the survey respondents who said they get spam are getting a lot of it. More than half in our anti spam review reported receiving fraudulent solicitations, and 40 percent felt that spam had invaded their privacy. And based on our survey, we estimate that 650,000 consumers ordered a product or service advertised in spam in the month before the survey.

At the same time, spammers are getting harder to track, according to Paula Selis, senior counsel for the state attorney general in Washington, whose office has been particularly active in prosecuting spammers. "Maybe law enforcement has driven them offshore," she says. "That makes their job harder, but it also makes law enforcement's job harder."

Solutions. Use an effective filter (see our antispam software Ratings, available to ) and never reply to or buy anything from a spam message.

Almost four years after the passage of the federal Can-Spam Act, which gave law enforcers new anti spam tools to use against cyber thieves, its effectiveness is still in question. While bringing some accountability to commercial e-mail and giving officials legal tools, it legitimized some spam and pre-empted strong state laws.

Since 2004, the Federal Trade Commission has brought 26 cases against spammers using the act, according to Lois Greisman, associate director in the FTC's division of marketing practices. Courts awarded close to $13 million in those cases. Two criminal spam cases were prominent in 2007. This spring, Robert Soloway, a Seattle-based Internet marketer, was indicted for allegedly sending tens of millions of pieces of e-mail, much of it promoting bulk e-mail services, over four years. He pleaded not guilty. Earlier this year, Jeffrey Goodin, a phisher from Azusa, Calif., became the first spammer to be criminally convicted under Can-Spam. His sentence: almost six years.