We are all concerned about possible regulations that may be brought in by the governments of the world concerning the flying of hobby drones. In recent months, a group of investigators in the USA (the UAS America Fund) have drafted a set of rules governing the flight of 'micro unmanned aircraft', which includes a report that suggests that these aircraft should be treated differently than others of a bigger size.
This report suggests that small drones (less than 1.4Kg) may actually cause as little damage as a small to medium bird. Now, birds have been a cause of concern for the aviation world since it came into creation; a bird flying into your engine is never a good idea. However, as the technology has advanced, engineers have been able to set up some precautions to try and protect aircraft from 'bird strikes'. This reports suggests that these protective actions will also protect all manned aircraft against any accidently collision with a 'micro-drone'; hopefully good news for all hobby drone enthusiasts.
Of course, there are also general rules for flying any unmanned aircraft; you shouldn't fly above 400 feet and within 5 miles of any airport. Also see the image below for the CAA recommendations when flying an unmanned aircraft for non commercial use. These rules coupled with the fact that a collision with a small drone would very likely not lead to any casualties suggest that little if no further restrictions should be forced upon small UAVs. For larger unmanned aircraft however, the jury's still out.
CAA Drone Regulations:
Note: Even though this report suggests that collisions between manned and small unmanned aircraft may not lead to any fatalities, care when flying any unmanned aircraft should always be taken. A pilot may see a small drone, take evasive action which then causes a crash. Always be careful and considerate when flying.