To social network or not to social network

So I am a technology junkie. I facebooked and tweeted while in labor to provide everyone I know up to the minute updates on my labor progress.....I think that makes me officially a junkie! I have loved getting in touch with old friends and new ones via these social networks but I can't help but wonder if these sites lend themselves for people to address their issues to or about a person in a passive aggressive way. Without getting into friends which have made random comments on my page and theirs that seem directed square at me and the past that was. Now I know all about holding on to things in the past, my mother is the master of it, but at some point don't you just let it go and move on? Certainly you don't lay it out there for all the world to see?What are your thoughts on these social networking sites? Have you every taken the passive aggressive approach on them to deal with an issue you might have???