Why I'm here - the gray line of blogging.

I guess I should point out to anyone who stumbles upon this whose not from the Library (OCLS) - the staff here is in a course to learn about Web 2.0 technology, and we're all doing blogs. Not very interesting in and of itself, but fascinating none the less. I'm very interested in the gray area between our lives where the private and personal family life merges with the public/internet/work life. I have friends who used to write about the workplace all the time in their personal blogs - where is that line? - how much is a workplace violation of privacy, how much can affect job ratings, performance, and promotion. One of my friends left her old job, and burned all her bridges on her blog - and then almost got fired at her next job for blogging about workplace issues and concerns of a personal nature. How do we manage our thoughts and words while in this global area?