A recent Sophos analysis found that the U.S. produces far more spam than any other nation on earth.The study found that almost 57% of spam is generated in the U.S., followed by Canada at just under 7%, Hong Kong and China at 6.2% and South Korea at 5.8%.An interesting finding of Sophos\u2019 research is that more than 30% of spam is sent from computers that have been infected with a worm or Trojan horse and so are used as proxies for sending spam, completely unbeknownst to their owners.Part of the reason for the rapid increase in spam is the adoption of broadband in the home. The availability of these \u201calways on\u201d connections, coupled with the fact that too few home users have adequate firewall protection, presents an abundant opportunity for spammers to plant worms and Trojans and thereby use home-based computers for spreading spam. I suspect that South Korea placed so high on the Sophos list because that country is one of the heaviest users of broadband on a per-capita basis.Demonstrating the vulnerability of even a single computer to attack is the desktop machine in my office - as I write this, March is about 65 hours old and this computer has been on for about 54 hours during that period. Thus far, my firewall has blocked 243 separate \u201cinbound events,\u201d or attempts to access a port on this computer.Of course, the best thing that any individual can do to stop the spread of spam is never to buy anything advertised in a spam message. Cutting off the flow of cash to the people who send this stuff will change the economics of spam in the most fundamental way by making spamming financially unattractive. Other things that individuals can do is to make sure that anti-virus, anti-spam and firewall protection is installed and up to date, particularly for systems with a broadband connection.These steps sound so obvious that I\u2019m hesitant to even include them here, but the ability of virus writers and spammers to exploit these vulnerabilities is testament to how many people don\u2019t implement even these most basic of safeguards.