Incidents with drones are becoming more and more frequent these days.
A 47-old man was driving along the motorway in North Rhine-Westphalia when a drone crashed into his windscreen. http://www.thelocal.de/20150522/drone-smashes-into-car-windscreen-on-autobahn
Another drone was hovering above Marblehead Memorial Day parade while suddenly it lost control and hit a man on his head. http://boston.cbslocal.com/2015/05/25/drone-crashes-hits-2-people-during-marblehead-parade/
Stories like these raise questions about drone regulations.