Why Doesn't Someone Stop the Spammers?
Spammers are difficult to stop, partly because email as a technology is easy to use and hard to block. Each computer connected to the Internet has a unique numerical address called an Internet Protocol (IP) address. It's sort of like a telephone number. To send or receive information to or from a computer on the Internet, you have to know its IP address.
If a computer sends too much information—maybe too many spam emails—its IP address can be blocked by the recipient. This is what Internet service providers (ISPs) often do to curtail spam from a particular source. But if the owner of the sending computer changes the IP address, the ISP has to reblock the new address.
Because of this, spammers can evade being blocked by changing their IP address on a regular basis (or by sending from computers that they have hijacked and control through a botnet). They also move their operations overseas to countries that don't care or are more interested in making money than stopping spam.
Anti-spam laws have been enacted around the world in recent years by various countries, including the United States, to regulate commercial bulk email. Some high-profile spammers have been convicted but the laws have had little effect on reducing the total volume of spam. It keeps growing. However, spammers are being driven offshore to countries, such as China and Russia, where they are out of the grasp of anti-spam legislation.
According to a report by Message Labs, an email security company, the Australian Spam Act is one piece of legislation that has resulted in a "significant decrease in spam activity," driving known spammers to shut down activities or go offshore. Still, the volume of spam continues to climb (see Figure 6.3).
Figure 6.3 Email security company MessageLabs reported that spam constituted between 53% and 94.5% of email sent worldwide in 2004. Not much has changed; that volume is consistent today.