I actually thought I had found a way to delete these contacts. You can go to Network -> Add Connections -> Manage Imported Connections. Then you can delete thos

I actually thought I had found a way to delete these contacts. You can go to Network -> Add Connections -> Manage Imported Connections. Then you can delete those contacts (10 at a time - WTF). Sadly, those deleted contacts are still showing up in my "People You May Know" page. Hence, I think it is safe to assume that LinkedIn are doing a "Facebook delete".