Yeah, unfortunately, there is no expectation of privacy in public forums and blogs such as the ones here. In fact, if you look at the very bottom of the forum, you'll see "SEO by vBSEO 3.0.0 RC6 © 2006, Crawlability, Inc." So, not only is this place not private, but it's search-optimized.
By the way, I don't blame the owners here for that. Quite the contrary, they do have a business of sorts to run, and it's vital that they are able to generate traffic and increase the user base. Search optimization is just part of the business model so to speak.
Again, the I would basically treat this like "private" conversations at a crowded restaurant and assume that everything we type can be overheard so to speak. Again, the only way to ensure privacy is to create your own forum or blog that is customized for such a task.
Perhaps something can be done about the email specifically though, but that's something Jeffrey or Nate will have to comment on.