When you need to stack content access mechanisms together in Drupal, things can get pretty messy. When you add Organic Groups to the mix, it gets pretty wild. I’ve been faced more than once with the challenge of building a site that would be 90% internal, and 10% public. Unfortunately, than 10% of public content represents 50% of the site’s complexity, especially when configuring around the settings and functionality required for a nice Intranet.