It sounds like the people talking live in a town that has the word Creek in it's name, like Dawson's Creek for example. I think there is a website in the town called "creeksecrets" and the townspeople use it to post various things. Evidently the brother made a post regarding something that most townspeople think should have remained a secret or left unsaid. Now his family is associated with the post he made and are seen differently because of that.
I hope my interpretation helps. This is the best guess I can make without reading the story.