Pinging Knight

I was reading Keith Deven's entry about spam when I decided to write what I know about the topic. The entry was becoming quite long, so I thought that splitting it up might be better. The first part will be an introduction to spam and why I do not think it should be protected by the First Amendment. The next section will deal with how spammers manage to find your email and how they avoid being caught. The third part will discuss blacklists/whitelists and the challenge-response methods of dealing with spam. The fourth part will deal with filtering, particularly Bayesian filtering. In the last post, I will make some concluding remarks and link to additional anti-spam resources. Hope you will enjoy this series and find it useful. == == Who likes spam? No, not the magical meat that has 300% of your daily recommended value of sodium. I'm talking about the crap that floods the inbox of your email. Bank loans, hoaxes about lost African princes, porn advertisements, and various, ah, enlargement opportunities usually fall under this category. Those were some examples, but what exactly is spam? Paul Graham, a stalwart anti-spam soldier, has a very good definition: ==

To start with, spam is not unsolicited commercial email. If someone in my neighborhood heard that I was looking for an old Raleigh three-speed in good condition, and sent me an email offering to sell me one, I'd be delighted, and yet this email would be both commercial and unsolicited. The defining feature of spam (in fact, its raison d'etre) is not that it is unsolicited, but that it is automated.

It is merely incidental, too, that spam is usually commercial. If someone started sending mass email to support some political cause, for example, it would be just as much spam as email promoting a porn site.

I propose we define spam as unsolicited automated email.

== With that nice definition and the amount of people that hate spam, why not just outlaw it? Some states already outlaw spam in certain forms. The Washington anti-spam law allows people to sue spammers for $500 per message. The laws, however, are being challenged on the basis that spam should be protected by the freedom of speech. While it is an important consideration, there are at least one factor that should exclude spam from protection. Spam incurs many costs that are not paid by the sender. Junk mailers have to pay for postage. Door-to-door salespeople have to provide their own transportation (though they can be caught for trespassing sometimes). Telemarketers rarely incur extra charges on the phone bill—even so, there is now a National Do Not Call Registry. Spam, however, takes up bandwidth and goes through many servers that are nice enough to be part of the Internet. Many servers have to pay for their bandwidth, and spammers are freeloading. Additionally, some people still pay by the minute for net access; on dial-up, the minutes spent downloading spam can really add up. Why do spammers even do it? Spammers are hated and hunted by vigilante hackers. You'd also think the response rate would be fantastically low; and it is. But because it is so cheap to send out spam, it is still profitable. Just 3 people in a million need to bite for spam to recover its costs. It can cost as low as a couple hundred dollars to send millions of messages. Spamming is a business, and spammers make money. Next time: how spammers find you and how they avoid being found themselves.