This certainly would not compare with the damage caused by a 757 will a full fuel load. However, the reason for taking this small plane may not be the same as the larger planes.
All kidding aside -- what would someone want this type of plane for?
We need to be thinking what these targets might be and keeping our eyes open. The public at large definitely tends to take things more at face value. If a Freeper sees a middle east looking type taking pictures of a chemical plant, we don't assume that Achmed is just a foreign student taking tourist pictures. I know that I would be making a citizen's arrest on his ass, and he better have more than a boxcutter.