As I posted in the thread about it, some people were buying those and harvesting the drives for NASes, but I didn't want to spend the money to get multiple drives and a NAS box.
Plus there's two things that are going on that drive: backup copies of things which will also live on one of my internal drives (and, one thing I was interested in going for by getting the Pi to put it on my network, everything is on a different outlet and I think different breaker on the circuit breaker than my desktop is), and things which would be annoying but not an actual problem to lose (like "acquired" TV show episodes and movies). Of course I'm not putting my only copy of anything important on there.