Back in 2008, Facebook didn't have nearly the algorithmic curation it has now. For instance, you were much more likely to see posts from friends sharing content you disagreed with. Now, Facebook's algorithms have gotten so good at their primary business objective (increasing engagement with the platform) that you're guaranteed to see almost entirely content that you agree with.

If I share a picture of my kids, Facebook makes sure all of my relatives will see it. If I share a political post, it will only be seen by my friends that agree with me.

Ad targeting was also much less sophisticated back then (did Facebook even have ads yet at that point?).