Why don't Facebook and Google share event and calendar info?

With all the hoopla about how you can or can't take your friend list from one social network to another, I'd like to know when or if it will be possible to view your events across social networks. This is definitely a part of the new cloud-based Calendar Swamp we swim in. For instance, why can't I show my Facebook friends the calendar I've created in Google Calendar? If I accept an event invitation in Facebook, why can't I view that event in my Google Calendar? Assuming there's good access control in each direction, wouldn't this sharing mutually benefit both social networks, and move calendar sharing and its economic benefits forward?

If this is simply a case of each competitor not wanting to give the other a break, we should put the same pressure on them that got both services to support Open ID. In other words, we the customers need to demand it.

As for moving that friend list around, after all this time, I still don't know the right answer. It's one person's data versus another person's privacy. Maybe the same debate will trip up cross-social network calendar sharing. I hope not.