As the phenomenon of blogging gained more popularity, there was bound to be conflict between what is personal and what is work.
Several people indeed got fired because of what they wrote about work in their blogs. This is just one of the pitfalls of blogging.
The first person known to have been fired for their web log, was Dooce. It was a blog about the hectic life in a dot.com era startup. From there, the term "Dooced" was first used.
Another person, calling herself Queen of the Sky, got fired because of pictures on her web log in company uniform in a company aircraft.
Recently, Osman Husain wrote an updated guide on How to blog anonymously.