Facebook seem to have changed the way that the 'Info' tab 'Biography' section works.
It used to be possible to enter whatever information you liked in the fields: Activities, Interests, Music, Books, Movies, and Television. Facebook then made an attempt to link this to existing pages/groups which you could then decide if you wanted to 'Like' or not.
This morning I was prompted to update my Bio information and to choose pages that I 'Liked', when I chose not to do so all of my Bio information was deleted.
If I put information back in I am prompted to choose existing 'Liked' groups/pages, these pages are then used to consolidate friends' and global posts into one place on that subject. You automatically then 'Like' those pages, and this information appears on your wall.
As of yet I can't find a way to reverse this behaviour, and I can't find a way to get around the system - so I've changed all the fields in my Bio to something appropriate