Eliminate Your Computer Viruses or Risk Being Cut Off By Racsa
Tired of spam or unwanted emails? The Radiográfica Costarricense (Racsa) says it is doing something about it and each month, on average, it disconnects 35 users from its internet service because their computers computers contain a virus that generates spam or junk emails.

Racsa says that when it detects a problem, it calls the customer and notifies them of the disconnection until the virus is eliminated from their computer.

The head of the Asistencia Técnica de Racsa, Miguel Montero, explains that the measure is strict because if, on an international level, Costa Rica is labelled as a "spam" country, it can be blocked from the world wide web.

"This means, that beyond our borders, no website hosted in Costa Rica will be available to the web, nor can emails be received or sent from here. This occurred back in 2001", said Montero.

According to Racsa reports, so far this year, 106 customers were disconnected.

In all cases Racsa reports that the users became part of a "botnet", a jargon term for a collection of software robots, or bots, which run autonomously.

In 2001, Costa Rica ranked number 5 of countries generating the most spam. A number of countries began to block Costa Rican servers and all domains with the ".co.cr".

However, by 2004, Racsa was able to reduce the amount of spam generated from Costa Rica mainly due to measures and anti-spam regulations adopted by the state agency .

According to Montero, the spam filters that were put in place last March have effectively reduced the number of e-mails with spam virus by 97%. However, with all the controls, Montero, says that the spam levels are still to high due to the fact that most users don't take measures in eliminating viruses from their computers.

What is Spam?
E-mail spam is a subset of spam that involves sending nearly identical messages to numerous recipients by e-mail.

Spam is e-mail that is both unsolicited by the recipient and sent in substantively identical form to many recipients. Thus, a common synonym for spam is unsolicited bulk e-mail (UBE).

As the recipient directly bears the cost of delivery, storage, and processing, one could regard spam as the electronic equivalent of "postage-due" junk mail. However, this does not mean that all commercial email is spam; for example, some recipients may have opted in (i.e., willingly chosen) to receive the marketer's email.

Spam is growing exponentially, with no signs of abating. The amount of spam users see in their mailboxes is just the tip of the iceberg, since spammers' lists often contain a large percentage of invalid addresses.

In absolute numbers, in 1978 an e-mail spam is sent to 600 addresses. In 2007, the number of spam e-mails daily are more than 90.000.000.000.

Sending spam violates the Acceptable Use Policy (AUP) of almost all Internet Service Providers. Providers vary in their willingness or ability to enforce their AUP; some actively enforce their terms, some lack adequate personnel or technical skills for enforcement, while others may be reluctant to enforce restrictive terms against otherwise profitable customers.

Some popular methods for filtering and refusing spam include e-mail filtering based on the content of the e-mail, DNS-based blackhole lists (DNSBL), greylisting, spamtraps, enforcing technical requirements, checksumming systems to detect bulk email, and by putting some sort of cost on the sender via a Proof-of-work system or a micropayment. Each method has strengths and weaknesses and each is controversial due to its weaknesses.

Detecting spam based on the content of the e-mail, either by detecting keywords such as "viagra" or by statistical means, is very popular. Such methods can be very accurate when they are correctly tuned to the types of legitimate email that an individual gets, but they can also make mistakes such as detecting the keyword "cialis" in the word "specialist". The content also doesn't determine whether the email was either unsolicited or bulk, the two key features of spam. So, if a friend sends you a joke that mentions "viagra", content filters can easily mark it as being spam even though it is both solicited and not bulk.