CF could have said to KF "For various reasons we no longer wish to do business with you. In 24 hours we will stop redirecting to your servers. Please make appropriate arrangements." Had they done this, they would not have actually been censoring KF. They would also have been behaving like a responsible service provider by not cutting off service without notice.

Instead, they seem to have made the decision to do this in a way where they actually block access to KF, rather than in a way where they simply chose to stop doing business with KF. I could be wrong about this; maybe substantial notice was given, and CF reasonably believed that KF could have avoided service disruption. But given that they wrote a bunch of copy to go with this decision, including the copy for the redirect page, I'm inclined to think that this went off exactly as CF intended. They didn't give notice and attempt to prevent their customer from having service disruption because they wanted them to have service disruption, and they wanted everyone to know they wanted this.

CF should not do this. I don't care who KF is or what they've done. CF should either do right by their customers, or stop doing business with them in a responsible way. Not in a way designed to injure their customers. Especially after taking their money, but that's hardly the point.