I previously blogged about how troublesome categories can be in my post on an area of India where people were being pressured to declare themselves either Hindu or Muslim after centuries of practicing a hybrid religion. These issues of categories seems to come up on our modern age where it's necessary to put people into on group or another, so they can fill out a form or fit into a field in a computer database. Geoffrey Bowker and Susan Leigh Star wrote about precisely this phenomenon in "Sorting Things Out".
Here's another example of the problems that arise when it becomes possible to categorize things at a finer granularity than in the past. This story from the BBC reports on how an "Arctic Map shows dispute hotspots." New technology has allowed us to map the Arctic more precisely than before. As a result, circumpolar countries have more "facts" that they can use to argue over national boundaries. Fortunately, being cold-weather cultures with Northern temperaments, these countries will likely settle things in an orderly fashion.