Linking, after all, is part of the alternative economy of the blogosphere: if the goal of the blogger is to address as wide an audience as possible, any new readers driven to the blog is positive. That is not the case with all public journals or diaries, however. Especially on journaling sites like Livejournal.com, which emphasizes the interpersonal over the public journalistic, writers may indeed write for a clearly intended (often quite small) audience. When such journals get linked by one with much larger audiences, the exposure is often unexpected and undesired.
What is important to realize is that most bloggers post with a clear audience in mind, a fact even more pertinent to those users who purposefully prohibit search engines and do not look for as large an audience as possible. In such cases, their intended audience may be quite small and know the blogger as well as his or her beliefs, biases, and opinions on various subjects. Moreover, often their entries are not to be considered in a vacuum but are part of an ongoing conversation that spans over various posts and comments (and often even a variety of blogs). Observing such a conversation from the outside may easily take things out of context, because the context is only known to the intended audience (or sections thereof).