Everywhere else, red means stop and green means go. Here, the creator has chosen to reverse that to emphasize that they consider blocking to be good and allowing people to connect to be bad.

No attention is needed for the instances that are marked with red. They are federating.

The point is that it's portraying not blocking as an inherently negative thing, which isn't universally agreed upon at all. Plenty of people would say that they don't need any attention at all. It's not presenting objective in a neutral way, but rather labeling a group as bad.

Of course, it's probably fair to assume that the author has no intention of being neutral, but it's still valid grounds to criticize it as a data visualization.