While following this threat on slasdot, I came across this site by a system admin who tracks where the spam he fights on a daily basis originates from. This is further proof to break the myth of spamming that “Most spam originates from outside the US”. From this site, we can see that ~35% of spam originates from the US. I am not sure how the author is getting the country of origin from the IP address. I work at an ISP and know that even though all the IP addresses belong (are allocated) to us, they are all allocated to our customers (located outside the US). And we don’t SWIP them as we are required to :). So if any of our customers send out spam, for the rest of the world, it would look as if though it is originating from the US. Wonder how much of the 35% is made up of such spammers.