I've always found iCal's Birthday calendar to be really useful (the one that automatically pulls from Contacts). However, since turning on Facebook integration I now have loads more contact cards & birthdays in Contacts meaning the Birthdays calendar is simply flooded. There are so many displaying that I'm not really bothered about (a lot of acquaintances on Facebook). Is there a way to selectively choose which birthdays get pulled into the calendar? Or is there a way to hide all birthdays from Facebook contact cards?