agree -- the asymmetry offered by drones is ripe for exploitation. already happening:
http://www.cnet.com/news/drone-crashes-trying-to-deliver-dru... and
http://www.dailymail.co.uk/news/article-2670560/Drug-deliver.... more importantly, i'm guessing malicious actors may be testing out defenses in these articles:
http://www.huffingtonpost.com/2014/12/08/jet-drone-near-miss... (and the like). why put someone on the plane to take it down when you can just throw up a drone to fly into the turbine on approach?