FTC: ISPs Better at Blocking “Harvesters”

Nov 30, 2005 2:07 AM  By

Spammers are as busy as ever harvesting e-mail addresses, but Internet service providers block the vast majority of their attempts to flood consumers’ inboxes, according to a report released this week by the Federal Trade Commission.

The FTC report also found that consumers who post their Internet addresses on the Internet can prevent them from being harvested by using a technique called masking.

In a study using 150 undercover e-mail accounts — 50 each at one ISP that uses no antispam filters and at two ISPs that do use spam filters — the FTC posted the addresses on 50 Websites, including message boards, chat rooms, blogs, and USENET groups. These are places where spammers typically harvest e-mail addresses.

After five weeks, e-mail addresses at the unfiltered ISP received 8,885 spam e-mails, while the 50 addresses at one of the filtered ISPs received 1,208, and the 50 addresses at the other filtered ISP received 422. The first ISP that used filters blocked 86.4% of the spam and the second blocked 95.2%, according to the FTC. The commission did not identify any of the ISPs in the study.

The study also tested whether masking e-mail addresses — altering them by, for example, changing “@” to “at” to confuse automated software — could help e-mail users prevent having their addresses harvested. After five weeks, unaltered addresses received 6,400 pieces of spam, while the altered addresses received one.

“This encouraging result suggests that antispam technologies may be dramatically reducing the burden of spam on consumers,” said the report.