John Robb says that if money matters to you, then don't blog in public (scroll down a little bit).

I don't agree. Blogging has no more consequences than any other actions you take may have. Just on a bigger scale. If you blog something bad about your employer, you may get fired. Because you did that, you may turn off future employers.

But the same can be said if you say something bad about your current employer to someone. Blogging just magnifies the effect of that.

It goes back to what everyone said after a few bloggers got fired for blogging. They didn't get fired for blogging, they got fired for not using common sense and saying something in a public forum that could get them in trouble. Blogging won't get you fired. It's just a new medium to get yourself fired. Probably faster than normal too.