Oh well, i sold them off to the passing caravan...
best thing is to actually leave 1 or more item in them to keep them as finished goods bin (or whatever type).. that way, they won't get hauled to a furniture pile which might be miles away from the finished goods (or whatever) pile.. and your dwarves won't have to lug one or more of the items they want to store all the way over to the furniture pile before lugging the whole (possibly filled) bin back.