This one is interesting. When I first saw the title it brought me back to the golden days when I would hack Coke and Pepsi machines (it was cool to get to the debug menu). I then also read on how to hack those light signs that construction workers place, though I did nothing with the information. Overall the idea of it this even being possible doesn’t shock me the slightest.
A lot of the content in this article though is theoretical. It doesn’t discuss anything that actually happened, just that a contractor that works for a IT consulting firm tested these wireless sensors. The end result was that even the most basic of security practices weren’t being followed (i.e.: no encryption with data), and these are placed in some major US cities like Washington D.C. and San Francisco.