The article is of course biased.
MCI has data centers, where you put your servers and connect to their bandwidth. Anyone can host anything.
What happened is enough pressure was put on them to cancel their contract with a customer, due to the negative publicity.
This presents a slippery slope, because anti porn crusaders could do the same thing, etc. It could very well lead to censorship of ideas by pressuring hosting places to refuse service.
The company did nothing illegal, they weren't spammers. Yes, their software is spam software, but writing it is in no way illegal.
--Scott