An intruder stealing cell phones isn't all that weird to me(if they were actually stolen).
They will bring about as much money as a used DVR, or TV and much easier to pocket. Actually there is a big market for used cell phones, just check ebay, Craigslist or any of the resellers on the net. It appears cell phone theft is very common and on the rise in most states from what I googled. Here in FL a few years back there was a rash of stolen cells being quickly sold and used for large volumes of overseas calls until the service was cut off.