The article spends most of its time (and apparently the discussion spent much of its time) discussing the legal basis for blacklists (lists of IP addresses on the Internet known or believed to be the source of SPAM.
Some (mostly the bulk email service providers) that it shouldn't be legal for customers to use blacklists or for third parties to provide them because they form a kind of censorship that can prevent legitimate email (including government and corporate notifications sent by legitimate bulk-mail services) from getting through.
This may be an interesting discussion if the black list is set up on a government site, but in private hands, I don't understand the argument. There are a number of providers who make black lists available via the internet using a number of techniques and although they are not a very precise mechanism, they are effective at cutting down a substantial amount of SPAM.
I have been making use of them for years and they catch a couple hundred messages a month. I don't check every message, but I have had very few complaints of messages not getting through.
If, however, by some freak of government, somebody is able to outlaw black lists, these companies are going to be more upset to find that more network administrators are moving to white lists, lists of hosts known NOT to send spam. This raises the bar substantially for good behavior.