Blogging is a much more personal experience than article writing--at least it can be. Blogging is where you can choose to be your authentic self or try on any--or many-personas. You can blog under your own name or a variety of pseudonyms.
The decision of how much of yourself you are willing to divulge to the world at large can affect your career, whether that be as a freelance writer or an x-ray technician. It can also be affected by age. Teenagers living at home, for example, may not want to blog freely about family matters or teen angst--at least not under their own names.
Just as Facebook entries have cost people their jobs or livelihoods, so can blogging. It's just something to consider as part of your determination for how much of yourself you are willing to reveal.