Your reader is hostile
In your letter and poster defending your client, you should assume your reader is hostile to the subject or to your approach to it: rehabilitating someone’s image who has engaged in problematic behavior. On page 96 of our textbook, Table 5.1 offers a column of “Try This . . .” if your audience is neutral or positive, hostile, or part of the problem Reply how you could adopt the three options for addressing a hostile audience for either the letter or poster. Put our reply in bullet form, specifically one bullet per suggestion.
If you want to explore some of the hostility toward your client, reread the discussions about your client. Most posts were quite explicit in their dissatisfaction.