Bob wants the ability to only see posts from other users he knows, he does not want to see posts from someone he is not friends with.
User: Bob who wants to see posts from his friends
Feature: A log in system which only allows a user to access the main page unless they have an account, so they must sign in or log in when first accessing the page.
Business value: Allows the user to interact with a personalized website, where no user will see the same website after logging in.
User Story:
Bob wants the ability to only see posts from other users he knows, he does not want to see posts from someone he is not friends with.