For all the positives that come with the use of drones, it is also true they can be used to injure, harm or terrorize. I'm glad I'm not the security director for a large stadium complex!
An interesting factoid for you is that with the advent of guns, assassination attempts went way up. Prior to this, you needed to get close enough to use a knife, sword, or I expect a bow and arrow. There is a reason the king, emperor and czar had a "cup bearer," omeone to test the drink for poison.
The next "innovation" I'm waiting for is the suicide-less car bomb, with an autonomous car bringing the explosives to their destination. Not something I'm wishing for, but I expect to see it happen eventually.
