I think I've been lucky in that I got to experience some of the pitfalls (and pleasures) of being a public personality through Armageddon, which prepared me for the yuckier aspects of online interactions. It takes a decent amount to get me upset online, because when you've experienced incidents like people creating virtual puppets of you in order to sexually abuse them and send you a log of the events, a bad review seems fairly insignificant.
So here's my question - when you're blogging, how much is this a concern for you? Do you find yourself thinking of the people reading the post or do you just let the flow occur? Do you deliberately edit some things out? Do you separate out "public you" and "private you"? How much of blogging is playing a role?