One thing that was really buried in that article was this bit:
> At some point your IP range is bound to be banned, either by one asshole IP neighbor sending spam, one of your users being pwned [emphasis mine], due to arbitrary reasons, by mistake, it doesn't matter. It's not if, it's when.
In other words, at least some of the time, the one of his users' accounts had been compromised, and as a result, his servers were actually sending out spam. But rather than take responsibility for detecting and blocking outgoing spam on his own servers, he's blaming The System for doing exactly what it was meant to do.
> At some point your IP range is bound to be banned, either by one asshole IP neighbor sending spam, one of your users being pwned [emphasis mine], due to arbitrary reasons, by mistake, it doesn't matter. It's not if, it's when.
In other words, at least some of the time, the one of his users' accounts had been compromised, and as a result, his servers were actually sending out spam. But rather than take responsibility for detecting and blocking outgoing spam on his own servers, he's blaming The System for doing exactly what it was meant to do.