Perhaps I'm the only one who thinks this, but I always find it incredibly boorish when people post political status updates on Facebook. They always have a smug condescension about them, as the person (giddy with the mind projection fallacy), assumes that every one of their acquaintances can't wait to hear their latest thoughts on Palin, Obama and everything else that we're already frustratingly overexposed too. They're rarely saying anything actually original or insightful either, just boilerplate and talking points repeated as if they're hilarious bon mots.
The thing I wonder is whether the people stop and consider what fraction of the audience agrees with them (it's always lower than you think) and whether those who disagree are likely to appreciate the verbal intrusion (they're not). Facebook isn't twitter, where people are explicitly signing up to read your nonsense. People may friend you for many reasons, not all of which involve wanting to read your every thought. It's like if you happened to run into an acquaintance from work that you hadn't seen in a while. Would you launch into a tirade about abortion or gay marriage? Of course you wouldn't. And yet give people a keyboard, and they suddenly feel that no thought is too contentious to not be imposed on everyone you've ever met. This is a thoroughly bipartisan feeling of mine - I may agree with some of the conservative sentiments, but I feel just as put off by their airing in this forum, knowing that plenty of other people won't like them.
That's why I prefer the blog. If you want to read my political writings, you have to seek them out. I'm not press-ganging my friends against their will into being an audience for my screeds. The scheme is an opt-in one, not an opt-out one, and the audience thus selected for people who, by revealed preference, are happy to read my rantings, however inane and reactionary.