How much do you want that interview?
Not only can blogging get you fired, it can also prevent you from getting hired.
Randy Cohen, in his Ethicist column at the New York Times, responds to a woman upset after she was Googled before a job interview. She had written in her blog that someone on the search committee was a belligerent jerk; when he read the blog, he canceled the interview.
Was he ethical? Cohen says that although there are problems with Googling potential employees (accuracy, questions of sex and race, information about your personal life), ethics isn't one of them.
Even if her lack of tact hadn't kept her from being hired, her lack of common sense should have.