A number of years ago, so long ago in Internet time that we still called blogging "web logging," a friend of mine asked me to check out his personal web log. I immediately sensed trouble could be brewing because not only was he taking direct shots at his then-employer, but he was naming names. Even back then, when we could all naively assume nobody would ever notice what we were posting to our personal websites, I thought it was a very bad idea to bad-mouth your boss in public, especially when potentially anybody could stumble upon your posts.
As things have devolved over the years, it's now become a very bad idea to bad-mouth your boss in private, too. Even if your negative comments are posted to a password-protected site and you've made those comments on your own laptop on your own time... you could still get in trouble. Check out this chilling article in the Wall Street Journal, which suggests that not only is Big Brother watching your every keystroke, but he'll not hesitate to fire your bad-mouthing rear-end if you're not careful.