How is the feed used against Titus and Violet at the end of Part One? What is the point of the attack?

At the end of Part I, the police turn off Titus and Violet's feeds in order to stop their chanting at the protest. They turn off the feeds of Titus' other friends as well. In this, as well as in the beating of the old man, the group is marked as outcasts..... outcasts who will later find themselves in danger. What they do not immediately realize, however, is the the old man also has a feed.... a feed that has malfunctioned. In touching the group, he has infected them.