How your blog can ruin your career prospects

There may have been a certain amount of talk of late with regard to business blogging faux pas, but what of personal blogs?
Mel drew my attention to a very interesting article which shows how job candidates’ blogs ensured their failure in the job hunting process.
As an employer I found it quite revealing to read some of the anecdotes and, to be frank, I probably would react in a very similar way.
What never ceases to amaze me is the things that some people post in their blogs. Most of the blogs I read on a regular basis would contain a mixed back of technical, business or political commentary. Some may contain personal references, but even those would not reveal anything too embarassing about the author or their employers.
However, if you dip into some of the blogs being aggregated by POTB or any of the other blog collections, you will find some very revealing thoughts.
One example that springs to mind is of someone villifying a close relative on their blog. Surely something that personal should be kept private?